Checks | Action | ||||||||
---|---|---|---|---|---|---|---|---|---|
Definition: The problem may or may not turn the Malfunction Indicator Lamp (MIL) or store a Diagnostic Trouble Code (DTC). | |||||||||
Preliminary Checks |
| ||||||||
Electrical Connections or Wiring | Poor electrical connections or wiring can cause most intermittent problems. Perform a careful check of the suspected circuit for the following:
| ||||||||
Road Test | If a visual/physical check does not locate the cause of the problem, drive the vehicle with a J 39200 connected to a suspected circuit or use a scan tool. An abnormal voltage or scan reading, when the problem occurs, indicates the problem may be in that circuit. | ||||||||
Intermittent Malfunction Indicator Lamp (MIL) | The following can cause an intermittent MIL and no DTCs:
| ||||||||
Loss of DTC Memory | Check for loss of DTC memory by disconnecting the Engine Coolant Temperature (ECT) sensor and idling the engine until the MIL turns ON. An Engine Coolant Temperature (ECT) DTC should store and remain in memory when turning OFF the ignition for at least 10 seconds. If not, the PCM is malfunctioning. | ||||||||
Additional Checks | Check for an open diode across the A/C compressor clutch and for other open diodes. |