Test W: Intermittent Problem
NOTE:
Intermittent problems are difficult to diagnose. The ABS ECU only stores codes if it receives more than 8 volts at pin No. 20. A code 16 will be present whenever ECU has power, if there are no other problems. A stored code will be erased after 50 ignition cycles. If a code is tested and no problem is found, problem may be intermittent. If ABS light is on and no codes are present, go to TEST V: NO CODE
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- Clear Codes & Reconnect Components
Remove breakout box. Reinstall any components previously removed. Clear trouble codes. Turn ignition on with engine off. ABS warning light should come on for 3 seconds, then go out. If ABS warning light comes on for 3 seconds, then goes out, go to step 3 . If ABS warning light stays on, go to next step. - Connector/Terminal Check
Check all affected component connectors for bent or backed out terminals, damaged connector terminal locks, and damaged connector wedges. Also check intermediate connectors. Repair or replace components as necessary. Go to step 7). If no damaged components are found, go to next step. - Wiggle Test
Turn ignition on. While observing ABS warning light, wiggle affected or suspect circuit from one end of circuit to other. If ABS warning light comes on, go to step 5 . If ABS warning light does not come on, go to next step. - Verifying All Circuits Have Been Tested
Ensure all affected circuits related to trouble code have been tested. If all affected circuits have been tested, turn ignition off. Go to step 7). If all affected circuits have not been tested, go to step 3 and check next circuit. - Retrieve Codes
Turn ignition off. Following procedures in CODE RETRIEVAL EQUIPMENT HOOKUP and RETRIEVE ABS TROUBLE CODES under PRETEST CHECKS , retrieve trouble codes. If trouble code retrieved is different than code being serviced, go to appropriate TEST under DTC TESTS . If trouble code retrieved is not different than code being serviced, repair wire or terminal as necessary. Go to step 7). - Verifying All Appropriate Diagnostic Procedures Have Been Performed
Ensure following items have been performed:- Verify PRETEST CHECKS have been performed and a trouble code retrieved.
- Verify all steps of trouble code DTC TEST have been performed.
- Verify all steps of SYMPTOM TESTS have been performed.
- Verifying Repair
Clear all trouble codes. Turn ignition off. Following procedures in CODE RETRIEVAL EQUIPMENT HOOKUP and RETRIEVE ABS TROUBLE CODES under PRETEST CHECKS, retrieve trouble codes. If Code 16 is set, diagnosis is complete and system is functioning properly. If trouble code being diagnosed returns, go to step 4 . If a different trouble code is set, go to appropriate TEST under DTC TESTS .