Mechanics

ANTI-LOCK BRAKE LIGHTS

1994 Lincoln Town Car

Brakes problem
1994 Lincoln Town Car V8 Automatic

I noticed that the Anti-Lock Brake Lights suddenly turned on. I checked the computers and picked up codes 31 and 33. My mechanic told me that one of the computers may be fried. My Question is if the computer is the ECU, or is something else. The anti-lock brakes issue has contributed to the air-suspension in a way that the suspension components dies too.
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Mendotatech
July 16, 2010.



I don't think it's the ABS computer, 31= left front wheel speed sensor, 33= right rear wheel speed sensor. Check
1. DTCs 31, 35, 41, 55 Or 75: Check Left Front Sensor Turn ignition off. Disconnect ECU 55-pin connector. ECU is located in engine compartment on bracket attached to radiator support. Connect Breakout Box (014-00322) and ABS Adapter (T90P-50-ALA). Measure resistance at pins No. 30 and 48 on breakout box. If resistance is not 800-1400 ohms, go to next step. If resistance is 800-1400 ohms, go to step 3). 2. Disconnect left front wheel sensor connector. Measure resistance between sensor terminals. If resistance is 800-1400 ohms, repair circuit No. 521 (Tan/Orange wire) or No. 522 (Tan/Black wire). If resistance is not 800-1400 ohms, replace wheel sensor. 3. Turn ignition off. Turn off air suspension (if equipped). Raise and support vehicle. Spin left front wheel at about one revolution per second. Measure voltage at breakout box pins No. 30 and 48. If voltage is.10-1.40 volts AC, go to step 4). If voltage is not.10-1.40 volts AC, check sensor mounting, sensor air gap and toothed ring for damage, wear and misalignment. Repair as necessary. 4. Check for continuity between breakout box pins No. 30 and 60. If continuity exists, go to next step. If no continuity exists, go to step 6). 5. Disconnect left front wheel sensor connector. Check for continuity between each wheel sensor connector terminal and body ground. If continuity exists at either terminal, replace wheel sensor. If continuity does not exist at both terminals, repair circuit No. 521 (Tan/Orange wire) or No. 522 (Tan/Black wire). Reconnect sensor. 6. Check continuity between breakout box pin No. 60 and ground. If continuity exists, go to step 7). If continuity does not exist, repair circuit No. 57 (Black wire). 7. Check left front wheel bearing end play. Check toothed sensor ring for damage. Service as necessary. If no problem is found, verify symptom still exists. Turn air suspension on (if equipped). 8. DTC 32, 36, 42, 56, 72 Or 76: Check Right Front Sensor Turn ignition off. Disconnect 55-pin connector from ECU. ECU is located in engine compartment on bracket attached to radiator support. Connect Breakout Box (014-00322) and ABS Adapter (T90P-50-ALA). Measure resistance between breakout box pins No. 29 and 47. If resistance is not 800-1400 ohms, go to next step. If resistance is 800-1400 ohms, go to step 10). 9. Disconnect right front wheel sensor connector. Measure resistance between sensor terminals. If resistance is 800-1400 ohms, repair circuit No. 514 (Yellow/Red wire) or No. 516 (Yellow/Black wire). If resistance is not 800-1400 ohms, replace wheel sensor. 10. Turn ignition off. Turn off air suspension (if equipped). Raise and support vehicle. Spin right front wheel at about one revolution per second. Measure voltage between breakout box pins No. 29 and 47. If voltage is.10-1.40 volts AC, go to step 11). If voltage is not.10-1.40 volts AC, check sensor mounting, sensor air gap and toothed ring for damage, wear and misalignment. Repair as necessary. 11. Check for continuity between breakout box pins No. 29 and 60. If continuity exists, go to next step. If no continuity exists, go to step 13). 12. Disconnect right front wheel sensor connector. Check for continuity between each wheel sensor connector terminal and ground. If continuity exists at either terminal, replace wheel sensor. If no continuity exists at either terminal, repair circuit No. 514 (Yellow/Red wire) or No. 516 (Yellow/Black wire). Reconnect sensor. 13. Check for continuity between breakout box pin No. 60 and ground. If continuity exists, go to step 14). If continuity does not exist, repair circuit No. 57 (Black wire). 14. Check front wheel bearing end play. Check toothed sensor ring for damage. Service as necessary. If no problem is found, verify symptom still exists. 15. DTC 33, 37, 43, 57 Or 77: Check Right Rear Sensor Turn ignition off. Disconnect 55-pin connector from ECU. ECU is located in engine compartment on bracket attached to radiator support. Connect Breakout Box (014-00322) and ABS Adapter (T90P-50-ALA). Measure resistance between breakout box pins No. 27 and 45. If resistance is not 800-1400 ohms, go to next step. If resistance is 800-1400 ohms, go to step 17). 16. Disconnect right rear wheel sensor connector. Measure resistance between sensor terminals. If resistance is 800-1400 ohms, repair circuit No. 523 (Red/Pink wire) or No. 524 (Pink/Black wire). If resistance is not 800-1400 ohms, replace wheel sensor. 17. Turn ignition off. Turn off air suspension (if equipped). Raise and support vehicle. Spin right rear wheel at about one revolution per second. Measure voltage between breakout box pins No. 27 and 45. If voltage is.10-1.40 volts AC, go to step 18). If voltage is not.10-1.40 volts AC, check sensor mounting, sensor air gap and toothed ring for damage, wear and misalignment. Repair as necessary. 18. Check for continuity between breakout box pins No. 27 and 60. If continuity exists, go to next step. If no continuity exists, go to step 20). 19. Disconnect right rear wheel sensor connector. Check for continuity between each wheel sensor connector terminal and ground. If continuity exists at either terminal, replace wheel sensor. If no continuity exists at either terminal, repair circuit No. 523 (Red/Pink wire) or No. 524 (Pink/Black wire). Reconnect sensor. 20. Check for continuity between breakout box pin No. 60 and ground. If continuity exists, go to step 21). If continuity does not exist, repair circuit No. 57 (Black wire). 21. Check differential housing and rear wheel bearings for excessive play. Inspect for damaged teeth on sensor ring. Service as necessary. If no problems exist, verify symptom. Turn air suspension on (if equipped). 22. DTC 34, 38, 44, 58, 74 Or 78: Check Left Rear Sensor Turn ignition off. Disconnect 55-pin connector from ECU. ECU is located in engine compartment on bracket attached to radiator support. Connect Breakout Box (014-00322) and ABS Adapter (T90P-50-ALA). Measure resistance between breakout box pins No. 28 and 46. If resistance is not 800-1400 ohms, go to next step. If resistance is 800-1400 ohms, go to step 24). 23. Disconnect left rear wheel sensor connector. Measure resistance between sensor terminals. If resistance is 800-1400 ohms, repair circuit No. 518 (Light Green/Red wire) or No. 519 (Light Green/Black wire). If resistance is not 800-1400 ohms, replace wheel sensor. 24. Turn ignition off. Turn off air suspension (if equipped). Raise and support vehicle. Spin left rear wheel at about one revolution per second. Measure voltage between breakout box pins No. 28 and 46. If voltage is.10-1.40 volts AC, go to step 25). If voltage is not.10-1.40 volts AC, check sensor mounting, sensor air gap and toothed ring for damage, wear and misalignment. Repair as necessary. 25. Check for continuity between breakout box pins No. 28 and 60. If continuity exists, go to next step. If no continuity exists, go to step 27). 26. Disconnect left rear wheel sensor connector. Check for continuity between each wheel sensor terminal and ground. If continuity exists at either terminal, replace wheel sensor. If no continuity exists at either terminal, repair circuit No. 518 (Light Green/Red wire) or No. 519 (Light Green/Black wire). 27. Check for continuity between breakout box pin No. 60 and ground. If continuity exists, go to step 28). If no continuity exists, repair circuit No. 57 (Black wire). 28. Check differential housing and rear wheel bearings for excessive play. Inspect for damaged teeth on sensor ring. Service as necessary. If no problems exist, verify symptom. Turn air suspension on (if equipped).

Merlin2021
Jul 16, 2010.