D. CHART 1 l INTERMITTENT CODE OR A SYMPTOM AND NO CODES (Centd.)
C1 l 2 Diagnosis of an
NOTICE: Do not use any other procedures in this manual (except for the suggestions listed below) when
trying to solve an intermittent problem. Use of any other procedures for this kind of problem can result in the
replacement of non-defective parts.
Many intermittent problems are caused by faulty electrical connectors or wiring. Diagnosis must include a
careful inspection of the indicated circuit wiring and connectors. Example: an intermittent Code 35 (Oil
Pressure Sensor High) should cause suspicion of a problem in the following areas associated with the Oil
1. Wire #s 530 (signal line), 416(+5 Volt line) or 452 (ground line).
2. The Oil Pressure Sensor connector or ECM connector.
3. An intermittent in the Oil Pressure Sensor (least likely)
A good check list to run through includes the following:
Check for poor mating of the connector halves or terminals not fully seated in the connector body
Look for improperly formed or damaged terminals. All connector terminals in the problem circuit should
be carefully reformed to contact tension.
Electrical system interference caused by a defective relay. ECM driven solenoid, or a switch causing an
electrical surge. Look for problems with the charging system (alternator, etc.). In certain cases, the problem
can be made to occur when the faulty component is operated (as in the case of a relay).
After repairs or adjustments have been made, clear the codes and confirm that the Check Engine* Light
does not come on (except for the 5 second bulb check when the ignition is first turned on). Also run the
engine to see if that problem is cured. If the Check Engine Light stays on, refer to the START Chart on