DTC 15

Code 15 Diagnostic Chart And Circuit Diagram:

***UPDATED BY TSB #F01391, AUGUST 13, 1991

Severe cold temperatures may cause the MIL to illuminate momentarily after a cold start, during engine warm-up. This may be due to delayed oxygen sensor response time.

If this problem is encountered, use the Self-Diagnosis Checker or equivalent aftermarket "Scan" tool to confirm Code 15 exists. If it does, replace ECU with a modified unit from the rebuild program as explained in TSB #F01391.