GM Full Size Vans 1987-1997 Repair Guide

Clearing Codes

Print

See Figures 1 through 15

Stored fault codes may be erased from memory at any time by removing power from the ECM for at least 30 seconds. It may be necessary to clear stored codes during diagnosis to check for any recurrence during a test drive, but the stored codes must be written down when retrieved. The codes may still be required for subsequent troubleshooting. Whenever a repair is complete, the stored codes must be erased and the vehicle test driven to confirm correct operation and repair.


WARNING
The ignition switch must be OFF any time power is disconnected or restored to the ECM. Severe damage may result if this precaution is not observed.

Depending on the electrical distribution of the particular vehicle, power to the ECM may be disconnected by removing the ECM fuse in the fusebox, disconnecting the in-line fuse holder near the positive battery terminal or disconnecting the ECM power lead at the battery terminal. Disconnecting the negative battery cable to clear codes is not recommended as this will also clear other memory data in the vehicle such as radio presets.



Click image to see an enlarged view

Fig. Fig. 1: Carbureted engine trouble codes



Click image to see an enlarged view

Fig. Fig. 2: Fuel injected engine trouble codes through 1995, except with 4L60E and 4L80E transmissions



Click image to see an enlarged view

Fig. Fig. 3: Fuel injected engine trouble codes through 1995 with 4L60E transmissions



Click image to see an enlarged view

Fig. Fig. 4: Fuel injected engine trouble codes through 1995 with 4L60E transmissions (continued)



Click image to see an enlarged view

Fig. Fig. 5: Fuel injected engine trouble codes through 1995 with 4L80E transmissions



Click image to see an enlarged view

Fig. Fig. 6: Fuel injected engine trouble codes through 1995 with 4L80E transmissions (continued)



Click image to see an enlarged view

Fig. Fig. 7: Trouble code list for 1996-97 gasoline engines



Click image to see an enlarged view

Fig. Fig. 8: Trouble code list for 1996[en dash]97 gasoline engines (continued)



Click image to see an enlarged view

Fig. Fig. 9: Trouble code list for 1987-93 diesel engines with manual transmissions and 1987 -90 diesel engines with automatic transmissions



Click image to see an enlarged view

Fig. Fig. 10: Trouble code list for 1991-93 diesel engines with 4L60E automatic transmissions



Click image to see an enlarged view

Fig. Fig. 11: Trouble code list for 1991-93 diesel engines with 4L60E automatic transmissions (continued)



Click image to see an enlarged view

Fig. Fig. 12: Trouble code list for 1994-95 diesel engines



Click image to see an enlarged view

Fig. Fig. 13: Trouble code list for 1994-95 diesel engines (continued)



Click image to see an enlarged view

Fig. Fig. 14: Trouble code list for 1996[en dash]97 diesel engines



Click image to see an enlarged view

Fig. Fig. 15: Trouble code list for 1996 diesel engines (continued)

 
label.common.footer.alt.autozoneLogo