Intermittent Conditions

WARNING: When the engine is operating, DO NOT stand in a direct line with the fan. DO NOT put your hands near the pulleys, belts or fan. DO NOT wear loose clothing.

NOTE: The conditions that set the DTC are not present at this time. The following list may help in identifying the intermittent condition.

Refer to any Technical Service Bulletins (TSBs) that may apply.
Review the DRB Freeze Frame information. If possible, try to duplicate the conditions under which the DTC set.
With the engine running at normal operating temperature, monitor the DRB parameters related to the DTC while wiggling the wire harness. Look for parameter values to change and/or a DTC to set.

CAUTION: Never probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool (8815) to perform diagnosis.

Visually inspect the related wire harness. Look for any chafed, pierced, pinched, partially broken wires and broken, bent, pushed out, or corroded terminals. Inspect and clean all PCM, engine, and chassis grounds.
If numerous trouble codes were set, use a wire schematic to help you find any common ground or supply circuits.
For any Relay DTCs, actuate the Relay with the DRBIII(R) and wiggle the related wire harness to try to interrupt the actuation.
For intermittent Evaporative Emission trouble codes perform a visual and physical inspection of the related parts including hoses and the Fuel cap. A co-pilot, data recording, and/or lab scope should be used to help diagnose intermittent conditions.
Use the DRBIII(R) to perform a System Test if one applies to failing component.
If any problems were found during the above inspections, repair as necessary. If no problems were found during the above inspections, test is complete.