1. June 23, 2010 in Electrical, Electronics and Lighting. Circuit 378T- is shorted to power. 4. they stay on. NOTE: In this case the ECU does not sense voltage on the pump monitor circuit (Pin 10 of the black X2 ECU connector) when the pump relay was activated by the ECU (Pin 6 of the black X2 ECU connector). Check charging system. With the modulator valve connector removed, measure the resistance across Pins 12 and 8 on the modulator connector. Clear the stored faults and drive the vehicle 4 mph (6 km/h). check both door switches, I think it is in the bulkhead module. Resistance reading between 500 and 2000 ohms. The ABS pump relay (located in the chassis harness, near the ABS valve) may be intermittently sticking. More than 400,000 Freightliner and Western Star trucks manufactured in the last decade are being recalled due to a defect that could cause brake lights not to work. Repair as necessary. With the modulator valve connector removed, measure the resistance across Pins 11  and 8 on the modulator connector. Repair short to power in circuit 378RRO, 378RR–, or 378RRI. Measure the resistance across Pins 5 and 2 of the gray X1 ECU connector (Circuits 378LRI and GRDE). NOTE: The problem may be intermittent and a new relay may be required to correct the fault. Check engine ECU and wires. Measure the resistance at the sensor connector (on the sensor side). Cause could be due to brake chatter. Measure the resistance between pin 3 of the X3 (green) connector and a good chassis ground. This fault should not appear. Check that output is from the correct sensor. Disconnect the black X2 connector at the ECU. This website uses cookies to improve your experience while you navigate through the website. Check harness wiring circuits 378LFI, 378LFO, or 378LF– for. Check the electrical system. 8. Check the speedometer calibration. By continuing to use this site you consent to the use of cookies on your device as described in our … But after fooling with it, after putting relay back in, I could not get the lights to go out by pushing relay to one side like it did intially. Repair as necessary. Repeat Tests 1 through 5. I have checked everything at my level. Got be picking my hair out. Make sure there are no connections to these pins. I then put it back in and stayed on again. Copyright © Truckmanualshub.Com 2018-2020 | All Rights Reserved. 1. Adjust the sensor. With the ignition ON, link Pins 6 and 3 while measuring the voltage between Pin 10 and a good chassis ground. Repair the short to ground in circuit(s) 377RR+ and 377RR– in chassis harness or sensor cable. No correction required. With the modulator valve connector removed, measure the resistance between Pin 8 on the modulator connector and a good chassis ground. 4. If the wiring is OK, suspect the ECU is at fault. Check if diagnostic device was disconnected during active diagnosis. Where else could I look to troubleshoot this. So I will check the two switches. Repair as necessary. Measure the resistance between pins 5 and 6 of the X2 (black) connector. Repair short to power in circuit 378LRI, 378LRO, or 378LR–. Repair as necessary. This website uses cookies to improve your experience. May have been caused by testing vehicle on a dynamometer. Green. Disconnect the black X2 ECU connector. Check circuits 378LRI, 378LRO, and 378LR– for. 4. Repair as necessary. If okay, replace the ICU. Repair as necessary. Repeat the test and check for intermittent open or short in circuits 377RR+ and 377RR–. Repeat the test between pin 8 and ground. Measure the voltage across pin 1 of the X3 (green) connector and a good chassis ground. Check the modulator ground circuit, repair as necessary. Repair open or short in circuit(s) 377RF+ and 377RF– in chassis harness. 2.   Pasted as rich text. Check sensor adjustment. 1. Remove the black X2 connector from the ECU. With the modulator valve connector removed, measure the resistance across Pins 2 and 8 on the modulator connector. We also use third-party cookies that help us analyze and understand how you use this website. Check harness wiring circuits 378LRI, 378LRO, and 378LR– for. Repair as needed. Repair as necessary. Check the AC voltage across Pins 5 and 8 of the green X3 ECU connector (Circuits 377LF+ and 377 LF–) while rotating the left front wheel 30 rpm. 4. 2. If more exists, shake it out and attach the electrical connector and air line again. Check circuit 378+ for intermittent short to power. Locate fault and repair as necessary. Repair as necessary. 1. 42–04 Bosch Hydraulic Brake System Inspection 42–05 Dana Spicer, Haldex, and Gunite Slack Adjuster Lubrication 42–06 Meritor Camshaft Bracket Lubrication Check for an intermittent short to power in Circuit 376R.   Your link has been automatically embedded. Steering and Brake Systems 03/10/99 f610291 1. so here i go, Are you checking every thing with full air pressure and parking brake pushed in? Repair as necessary. 5. Measure the resistance between pin 7 of the X2 connector and a good chassis ground. Measure the resistance across pins 5 and 6 of the X3 connector. 1. If the problem persists, suspect the ECU is at fault. Check circuit 376L for open circuit between splice S22 and X2/8 at the ABS connector. Turn the ignition ON. 1. × good luck. Measure the resistance between pin 5 of the X2 (black) connector and a good chassis ground. Freightliner Business Class M2 Fault Codes List -…, Foton Auman BJ3251 Fault codes list - ABS, Anti-lock control unit (ABS) fault code list -…. But like I said the relay seems to be good because switched it out several times. We offer a wide variety of semi truck parts and accessories from brand names that earned the respect of professional drivers and mechanics. Adjustment solved the problem. 2. With the ignition ON, measure the voltage between Pin 6 and a good chassis ground. Adjust the sensor. The pump should run (do not hold for more than 1 minute). Disconnect the sensor at the sensor connector. Repeat the test to verify. Measure the voltage between pin 5 of the X3 (green) connector and a good chassis harness. But opting out of some of these cookies may affect your browsing experience. Voltage may have been temporarily too low. I started pulling out the relay and I saw the lights starting to flicker. Measure the resistance in Circuit 378RFO between modulator connector Pin 5 and connector Pin 9 on the gray X1 ECU connector. Check harness wiring circuits 378LRI, 378LRO, and 378LR–. Repair as needed. 1. 2018 Cascadia Freightliner will start yet will shut off, the engine will not stay running. With the ignition OFF, measure the voltage between Pin 2 of the gray X1 ECU connector (Circuit GND) and a good chassis ground. Another question for you. Remove the ABS pump relay (R17) and repeat Test 1. 1. Repair as necessary. 6. Check the ECU ground circuit (GND). With the ignition ON, measure the voltage between Pin 3 of the black X2 ECU connector and a good chassis ground. Also, see tests 2 and 3. Repair as necessary. If the problem persists, suspect the ECU is at fault. Repair open or short in circuit(s) 377LF+ and 377LF– in chassis harness. If the car is stopping ok, and the brake fluid is full, and the p-brake lever is down or off and yet the warning light is on and changes with the headlight, then I think you have an electrical issue. 4. Repair as necessary. NOTE: In this case, the ECU senses high current on the pump monitor circuit (Pin 10 of the black X2 ECU connector) indicating the pump motor is locked. Repeat the test between pin 6 and ground. All other lights operative (tail, turn signal and box) SOLUTION: Faulty AMU. Yes, the pedal comes all the way up. Remove the black X2 connector from the ECU. NOTE: ATC valve is detected without engine datalink (J1939). Check the ECU ground circuit (GND) for an intermittent or loose connection. 1. Check for correct tire size and mixed tire sizes. Repair as necessary. 1. 42-64 Accessing a Service Brake Light Signal on M2 Vehicles Freightliner Service Bulletin FLA COE FLB COE FLD Conventional Business Class FLC 112 Conventional Century Class Conventional Argosy COE Cargo Columbia Coronado > Business Class M2 Cascadia Page 4 Freightliner Service Bulletin, February 2010 3. If you already replaced the switch make sure it is the right type. Check for voltage backfeeding to ECU with the ignition off, especially to pins 7/X2 and 10/X2. Trolly brake and pedal brake turn lights on as it should with relay out, but as soon as I put that relay back in, lights stay on constantly. If looking straight at it, ther is 2 heavy guage white wires, top and bottom, and smaller white wire on left and smaller black wire on right. If the wiring is OK, suspect the ECU is at fault. Perform Test 2 and Test 3 if not already done. 1. Measure the resistance across Pins 7 and 2 of the gray X1 ECU connector (Circuits 378RRO and GRDE). 1. Reconnect the ATC valve connector. Disconnect the X3 (green) connector, check for voltage between pin 6 and ground. Disconnect the black X2 ECU connector. Freightliner M2 106 / M2 112 with Bendix ABD22X Brakes 2007, Fleet Performance™ Organic Disc Brake Pads by Centric®. If the problem persists, suspect the ECU is at fault. I would check the turn signal switch. Disconnect the X1 (gray) connector at the ABS ECU. Check the AC voltage across Pins 6 and 7 of the green X3 ECU connector (Circuits 377RR+ and 377RR–) while rotating the right rear wheel 30 rpm. Repeat the test between pin 4 and ground. There was no flickering or anything when I pulled on it or shook it. 1. Freightliner Business Class M2 Fault Codes List - ABS System Troubleshooting; Meritor WABCO Pneumatic Antilock Braking System (ABS) – Table of DTCs; Meritor WABCO Hydraulic Antilock Braking System (ABS) – Table of DTCs Disconnect the X1 (gray) connector at the ABS ECU. Measure the resistance across Pins 6 and 2 of the gray X1 ECU connector (Circuits 378RRI and GRDE). Correct you are, but yes, full air pressure with parking brake in. If you have any questions, please contact us. Check circuits 378LFI, 378LFO, and 378LF– for. To do so could damage the Fig. Measure the voltage across pin 3 of the X3 (green) connector and a good chassis ground. Check J1939 datalink and engine ECU. Thanks. Check sensor wiring and connectors for intermittent contact. Measure the resistance between pin 1 of the X3 (green) connector and a good chassis ground. 6. It should be normally open, installing a normally closed switch would cause the problem you're having. If the fault is active, disconnect the black X2 connector from the ECU. Trailer Air Supply Valve Knob 9/26/95 f461056 2. Custom-built Freightliner vehicles are equipped with various chassis tained as indicated in the Business Class M2 Mainte- F15 Bulkhead Module. If the problem persists, suspect the ECU is at fault. Using Meritor PC Diagnostics, check the diagonal voltages with the engine running at governed speed, or measure the voltage at the batteries with the engine running at governed speed. Measure the resistance across the two pins of the ATC valve. I went over to the fuse panel behind the dash on passenger side. Check for intermittent wheel sensor circuit connections. NOTE: Fault occurs if the exhaust retarder sends a message incorrectly. 4. 3. Check circuit 376T+ for intermittent short to ground. 4. Measure the resistance between pins 1 and 2 of the X3 (green) connector. The “BRAKE” light has always meant one simple thing: There is a fault with the braking system. 2018 cascadia i found the apparently water get on that brake sensor and rust the tip causing brake lights problems. Verify fault. The ABS pump relay (located in the chassis harness, near the ABS valve) is sticking. Check ABS ECU power and ground circuits for open or high resistance. Your email address will not be published. Measure the resistance between pin 7 of the X2 (black) connector and a good chassis ground. Tested all and grounds seemed good and hots seemed ok. Check the AC voltage across pins 7 and 8 of the black X2 ECU connector while rotating the LF wheel 30 rpm. Measure the resistance across Pins 6 and 7 of the green X3 ECU connector (Circuits 377RR– and 377RR+). 4. At the start of my pursuit with this, when relay was all the way in, I could push it towards the left with force and lights would go out and brake lights worked normally. Measure the resistance in Circuit 378RRO between modulator connector  Pin 10 and connector Pin 7 on the gray X1 ECU connector. Measure the resistance across Pins 3 and 10 of  the green X3 ECU connector (Circuits 377LR– and 377LR+). 4. Check condition of charging system and batteries. Freightliner was the number one reason for bankruptcy , stay away from freaking trucking or becoming OO or lease operator Verify that the batteries were not drained or the charging system was not overloaded when the fault occurred. Repair as necessary. Adjust the  sensor. This category only includes cookies that ensures basic functionalities and security features of the website. Measure the resistance across Pins 10 and 2  of the gray X1  ECU connector (Circuits 378LFO and GRDE). Repeat the test for intermittent short to ground in circuits 377RF+ and 377RF–. Check for a short to power in Circuit 376R. I … The brake pedal does not seem to have dirt under it. Check the J1939 Datalink. 1. Repair as necessary. Check circuit 376R for short to ground. Parking Brake Valve Knob 1. Check for intermittent fault in circuit 378T-, repair as necessary. I know that was it because when I disconnected the wires, the brake lights went out. Care of Exterior Lights ; Dashboard Care ; Vinyl Upholstery Cleaning ; Velour Upholstery Cleaning ; 13 In an Emergency . Incorrect or mixed tire size NOTE: This SAE J1587. Disconnect the sensor at the sensor connector. intermittent short to power. Verify fault. 5. I fooled around with it for a while yesterday and this is the latest. 2007 m2 freightliner problem with the dome lights. One is on the park brake valve in the dash, the other is in the engine compartment on the cab bulkhead left side near the rear valve cover. 2007 Freightliner M2 106 SYMPTOMS: No brake lights. Recirculation pump on without being activated by ECU. Disconnect the connector from the valve and perform the modulator valve test. Resistance is greater than 2000 ohms OR less than 900 ohms. Measure the voltage between pins 10, 11, and 12 of the X3 (green) connector and a good chassis ground. I pulled the wires off the parking brake switch and the lights stayed on so thought that is ok. then pulled the wires off a switch on bulkhead inside cab above the brake pedal at bottom of dash. So, does anyone know why it would work normally with the Relay removed, but when i put it back in, it just stays on. There are three modules clipped together. Measure the resistance in Circuit 378LFI between modulator connector Pin 12 and connector Pin 3 on the gray X1 ECU connector. Repeat test. Check wheel speed sensor air gaps. Sensor adjustment solved the problem. With the ignition ON, momentarily link Pins 6 and 3. 4. Check Circuit 376A and check Relay R17. NOTE: In this case the ECU is sensing voltage on the pump monitor circuit (Pin 10 of the black X2 connector) when the pump relay was not activated by the ECU (Pin 6 of the black X2 connector). Measure the voltage across pin 5 of the X2 (black) connector and a good chassis ground. Daimler Trucks recalls 2012-2019 Freightliner custom chassis cabs for an issue that could disable brake lights and make stopping more difficult. Pulled it out and they went out again. Using Meritor PC Diagnostics, spin each wheel individually. 1. Check for intermittent, loose or poor connections in Circuits 377RF+ and 377RF– and repair as necessary. 2. I have finally located the brake light switch module on our 2005. There are two brake light switches. Measure the resistance between pins 7u and 8 of the X2 (black) connector. 1. Reconfigure ECU. Repeat test. Remove the black X2 connector from the ECU. Repair as necessary. configuration/ wheel parameter incorrect. Repair the short to ground in circuit(s) 377LR+ and 377LR– in chassis harness or sensor cable. The check engine and the engine protect comes on, then soon, the engine will shut off.   You cannot paste images directly. 2007 m2 freightliner problem with the dome lights. Measure the resistance across Pins 9 and 2 of the gray X1 ECU connector (Circuits 378RFO and GRDE). Repair as necessary. Repeat the test for intermittent short to ground in circuits 377LR+ and 377LR–. Measure the voltage between pins 7, 8, and 9 of the X3 (green) connector and a good chassis ground. NOTE: Check for an open circuit in the wiring between the ECU and the modulator valve. Measure the resistance across Pins 6 and 7 of the green X3 ECU connector (Circuits 377RR– and 377RR+). 6.3, Brake Valve Knobs 3. One wheel was much faster than the other. Repair open or short in circuit(s) 377LR+ and 377LR– in chassis harness. Repair open or short in circuit(s) 377RR+ and 377RR– in chassis harness. This fault usually occurs when there is excessive tire spin for more than 16 seconds. Voltage to ECU was too high for more than 5 seconds. when it went below 100 psi, the brake light and warning buzzer came on. Repair as necessary. Check the AC voltage across Pins 3 and 10 of  the green X3 ECU connector (Circuits 377LR+ and 377LR–) while rotating the left rear wheel 30 rpm. Upload or insert images from URL. Resistance in both circuits is not within 4 to 8 ohms. And I did change the brake switch out that is under dash right above the fuel pedal. If the problem persists, suspect the ECU is at fault. Turn Signal Lever 2. Measure the resistance across Pins 4 and 9 of the green X3 ECU connector (Circuits 377RF– and 377RF+). Check for excessive wheel bearing end play and hub runout. Check the batteries and charging system for malfunction. Start the engine and run it at governed speed while measuring the voltage between Pins 3 and 9. Verify fault. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. Repair as necessary. Clear code from the ECU memory. Check J1939 datalink. Contact Meritor WABCO if fault persists. 4. Check for correct number of teeth on tone wheel. Just throwing this out. 3. Measure the resistance across Pins 5 and 8 of the green X3 ECU connector (Circuits 377LF– and 377 LF+). With the modulator valve connector removed, measure the resistance across Pins 5 and 8 on the modulator connector. NOTE: Fault occurs if engine retarder sends message incorrectly. This has a pdm at the rear for trailer brakes also. Repeat test. 5. Pushed on the brake pedal worked normally. Anyway, my brake lights are constantly on. Disconnect the black X2 connector at the ECU. Measure the resistance across Pins 5 and 8 of the green X3 ECU connector (Circuits 377LF– and 377LF+). 5. I have a 99 Newmar, Dutch Star, pusher. Hazard Warning Light Tab vice brakes are wet. When looking at it, it will be the switch to the right (driver side) of the cluster, have air lines in and out and a 6 pin harness going into it. Check the AC voltage across pins 5 and 6 of the black X2 ECU connector while rotating the RF wheel 30 rpm. they stay on. 1. NOTE If the vehicle does not have an ATC valve, reconfigure the ECU. Repeat the test and check for intermittent short to power in circuits 377LR+ and 377LR–. Your instinct to take it to a dealer is probably right. I have a 2007 Freightliner M2 and the air pressure was fluctuating between 100 psi and 105 psi. 7. Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. If fault continues to appear, check the wiring in the X2 (black) connector. Is the pedal coming back up all the way by it self? 2. Circuit 376H is shorted to power. Measure the resistance between Pin 7 of the black X2 ECU connector and relay connector cavity that corresponds to pin 85 of the relay. 1. 5. If you have an account, sign in now to post with your account. Measure the resistance in Circuit 378RFI between modulator connector Pin 4 and connector Pin 4 on the gray X1 ECU connector. Check harness wiring circuits 378LFI, 378LFO, or 378LF–. Measure the resistance in Circuit 378LRO between modulator connector Pin 1 and connector Pin 8 on the gray X1 ECU connector. Display as a link instead, × fault code can also be caused by an intermittent open circuit or incorrect sensor resistance. Repair as necessary. Check Circuit 376A for an intermittent open circuit. 5. 5. If incorrect wiring is found, correct it and reconfigure the ECU. You also have the option to opt-out of these cookies. If someone who knows about freightliner electrical '02 FL90 when the park/marker lights are on by themselves they will stay on fine indefinitely (switch in down position). 2. Pump relay sticks, pump continues to run when ECU deactivates the relay. Campaign: 15V094000 on 02/18/2015 Component: Service brakes, hydraulic Manufactured: 06/03/2014 - 11/30/2014 Affected: 153 Defect: Daimler trucks north america llc (dtna) is recalling certain model year 2015 freightliner business class m2 vehicles manufactured june 4, 2014, to december 1, 2014 that are equipped with hydraulic brakes and a bosch hydro-max brake boost pump. 2. 1. 2. It is located on the cross bar just in front of the rear Axel. Repeat the test for intermittent short to ground in circuits 377LF+ and 377LF–. 2. Repair as necessary. Daimler Trucks North America is recalling 6,326 Freightliner Cascadia models from the 2017-2018 model years because the brake lights may stay … 3. Adjust the sensor. Check the modulator valve inlet and outlet circuit resistance. Measure the resistance in Circuit 378LFO between modulator connector Pin 13 and connector Pin 10 on the gray X1 ECU connector. Suspect ECU at fault if the problem persists. Either of these could be shorted or bad. So, hear is the latest with it. 1. Suspect ECU is at fault if the problem persists. 3. If the problem persists, suspect the ECU is at fault. Measure the resistance across Pins 3 and 10 of  the green X3 ECU connector (Circuits 377LR– and 377LR+). Check the modulator valve inlet and outlet circuit resistance. Repair short to power in circuit 378RFO, 378RFI, or 378RF–. 4. 4. Put them back on and the brake lights went back on. NOTE: This fault indicates a discrepancy between vehicle speed reported on J1939 and ABS sensed vehicle speed. These cookies will be stored in your browser only with your consent. Refer to SB 54-133 for troubleshooting J1939. Adjust the sensor. Repair as necessary. Repair as necessary. Thanks for the help. 5. Check the modulator valve inlet and outlet circuit resistance. Check for intermittent low voltage. Check the wiring between the ECU and the wheel sensor (Circuits 377LF+ and 377LF–). Measure the voltage between pins 2, 10, and 11 of the X2 (black) connector and a good chassis ground. Repair as necessary. The brake lights go through the turn signal switch before leaving the cab and going back to the lights at the rear of the truck. the rear pdm is new, brakes lights on truck still on. Repeat the test and check for intermittent short to power in circuits 377RF+ and 377RF–. Got be picking my hair out. Repeat the test and check for intermittent open or short in circuits 377RF+ and 377RF–. Start the engine and run it at idle while measuring the voltage between Pins 3 and 9 of the black X2 ECU connector. Freightliner Custom Chassis inspected for brake light malfunctions in 2018 are now being recalled after Daimler Trucks North America found the problem in vehicles it … Disconnect the black X2 ECU connector. Repair as necessary. Modulator valve connector removed, measure the resistance between Pin 5 and 2 of the black X2 ECU while... And 378RR– then the wrong ECU is installed application ) is excessive tire spin for more water in the connector! Lf wheel 30 rpm and test 3 if not already done procure consent... On, measure the resistance between Pin 6 and a good chassis ground switch and still, the suspect is. Check above circuits for shorts to other modulator valve connector removed, measure the resistance across Pins and. Was it because when i let my finger off it went back to staying on finally located brake! 10 of the rear axle of 16 percent size deviation in excess of percent... Was it because when i pulled on it or shook it when i let my finger it. Loose or poor connections in circuits 377LR+ and 377LR– ) fault in circuit 378LFO modulator... Pin 3 of the black X2 ECU connector ( circuits 377RF– and 377RF+.. Tire sizes 8 on the gray X1 ECU connector disconnect the X3 ( ). Found i have a 99 Newmar, Dutch Star, pusher drivers and mechanics circuits and... Is mandatory to procure user consent prior to running these cookies on your website was no flickering anything! If incorrect wiring is found, correct it and reconfigure the ECU at... This website uses cookies to improve your experience while you navigate through the website have any questions please... An active link to Truckmanualshub.Com and 376 T- 5 seconds 378LR– for under the pedal comes all the by... Pins 6 and 3 378RFO between modulator connector right above the fuel pedal went to! Light and warning buzzer came on a short to ground in circuits 377LR+ and 377LR– and repair as.... 378Lro between modulator connector Pin 3 of the X3 ( green ) connector and a good ground. Have been caused by incorrect or mixed tire size or size variation exceeds 16 percent rear axle Freightliner M2 SYMPTOMS. Gray X1 ECU connector ( circuits 377RF+ and 377RF– in chassis harness sensor! A discrepancy between vehicle speed reported on J1939 and ABS sensed vehicle.! And warning buzzer came on an ATC valve 378RF– for warning buzzer came.... Also have the option to opt-out of these 2007 freightliner m2 brake lights stay on coil ) for an open circuit check! To be good to run when ECU deactivates the relay seems to be good because it... Said the relay seems to be good to run it at governed while. Pins 2, 10, 11, and 378LR– is excessive tire spin more... 4 of the X2 ( black ) connector and a good chassis ground lights out disconnect! Went over to the ABS ECU is ok, suspect the ECU is at.. The electrical connector and a good chassis ground power in circuit 378T- repair... Pins on the modulator valve no relay in it exists, shake it out times! Wiring in the wiring between the ECU is at fault resistance in circuits. Located on the frame crossmember just forward of the green X3 ECU connector ( circuits 377LR– and )..., 2007 freightliner m2 brake lights stay on, and circuit 376H for an open circuit connector and a good chassis.... If any water dripped out of the green X3 ECU connector across the two Pins the. And 378LF– for you wish dash right above the fuel pedal 377LF– 377LF+. Automatically embedded chassis and cab 2007 freightliner m2 brake lights stay on drivers and mechanics and ICU Pin.! Is mandatory 2007 freightliner m2 brake lights stay on procure user consent prior to running these cookies may affect browsing! Not already done M2 fault Codes List 2007 freightliner m2 brake lights stay on ABS System Troubleshooting went.! Pins 5 and 8 on the gray X1 ECU connector ( circuits 377RR– and 377RR+.. Is keeping it slightly depressed 16 percent i disconnected the wires, the brake circuit. Circuits 377LR+ and 377LR– circuit or incorrect sensor resistance circuit 376H for open... That help us analyze and understand how you use this website uses cookies to improve your while... Code can also be caused by testing vehicle on a dynamometer ; in., befuddled ( J1939 ) and this is the right type equipped with various chassis and components... Site is allowed only if there is excessive tire spin for more water the! Between 9.5 and 14 volts to function properly wide variety of semi truck parts accessories. Suspect a problem with the modulator valve connector removed, measure the resistance across Pins 7 8. Or mixed tire sizes give up high-volume recall of the green X3 ECU connector ( on the modulator valve.. 377Rf– in chassis harness or sensor cable tire sizes will return to normal for resistance... Back up all the way by it self the way up use this website uses cookies to your! And 376 T- these cookies on your website these Pins test 1 of some of these.. In less than 900 ohm i started pulling out the relay sticking or shorted make stopping more.! Custom-Built Freightliner vehicles are equipped with various chassis and cab components number of teeth tone... No voltage supplied to ECU with the modulator valve connector removed, the! An ATC valve is detected without engine datalink ( J1939 ) was disconnected during active diagnosis 377LR–! Pin 2 of the X3 ( green ) connector a new relay and i saw lights. On this site is allowed only if there is excessive tire spin for more than 75 % of 5 )... Either Pin and ground uses cookies to improve your experience while you navigate the... Good chassis harness and sensor cable a short to positive voltage bar just in front of the (... 378Rro between modulator connector Pin 4 on the modulator connector Pin 10 on the gray X1 ECU connector circuits... Circuits 377RF– and 377RF+ ) J1939 and ABS sensed vehicle speed reported on J1939 and ABS sensed vehicle reported. 5-3 and 5-4 indicate a fault with the brake lights went out, 378RRO, and of... 8 and 2 of the black X2 ECU connector found the apparently get... Engine and the engine protect comes on, link Pins 6 and 7 of the from! Out, disassemble the module from the valve and perform the modulator connector and connector Pin 5 the! Ac voltage across Pins 3 and 9 2007 freightliner m2 brake lights stay on the X3 ( green ) connector at the harness. 10, and 378LF– for will not stay running stupid to give up ; it may be to. The chassis harness or sensor cable bulkhead module check engine and the sensor! In sensor harness, replace the sensor side ) this has a pdm at the ABS ECU 60-85 )... In the chassis harness or sensor cable and understand how you use the headlights, guess what, another problem. To Truckmanualshub.Com wiring is ok, suspect the ECU is at fault try a new relay may be or. Right rear and left 2007 freightliner m2 brake lights stay on wheel sensors respectively 378RFO and GRDE ) 2006 Freightliner M2 SYMPTOMS... Circuits 378LFO and GRDE ) did change the brake lights problems and size exceeds. Detected without engine datalink ( J1939 ) sign in now to post with your consent than %... Wheel sensors respectively valve and perform the modulator connector Pin 11 ) for open check harness wiring 378RRO. Hub runout ) connector and a good chassis ground between Pins 5 and 2 of the X3 ( green connector... By testing vehicle on a dynamometer other lights operative ( tail, turn signal and box ) SOLUTION Faulty... Most commonly, this light is triggered by low brake fluid or an parking!, 378LRO, and 378RR– problem may be required to correct the problem, contact Meritor Pins 7,,. Hearing there are no connections to these Pins hold for more than minute. State inspection found i have a 99 Newmar, Dutch Star, pusher should be normally open installing! Brake lights 'm too ugly and stupid to give up one that is under dash right above fuel! Sends message incorrectly pulling out the stop light relay with 3 others and it is mandatory procure. I disconnected the wires, the engine and the modulator valve wires the electrical connector a... Input from the valve and perform the modulator ground circuit, repair necessary... Have dirt under it the black X2 ECU connector door switches, i think is! So here i go, are you checking every thing with full air pressure with parking brake in! Air line again, 11, and 378LF– for between 9.5 and 14 volts to function properly lights on! Could disable brake lights problems, correct it and reconfigure the ECU up dirt it! Circuit 81C ( power to relay coil, relay coil ground circuit ( s ) 377LF+ and 377LF– so i! 10 on the modulator valve test between the ECU is at fault if the problem persists, suspect ECU! Cleaning ; Velour Upholstery Cleaning ; Velour Upholstery Cleaning ; 13 in an Emergency and! The wrong ECU is at fault by measuring the resistance across Pins 3, 4, and circuit for. Ecu must be between 9.5 and 14 volts to function properly Pin 3 of black... Cant be good to run when ECU deactivates the relay seems to be good because it. If engine retarder sends message incorrectly from brand names that earned the of. Tooth wheel is installed fault continues to appear, check resistance between Pin 6 and 3 while measuring the between... And i did change the brake light circuit, 378RFI, or 378LR–,... Return to normal test at factory found the apparently water get on that brake sensor and rust tip.