Intermittent Condition

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 TSB's that may apply.
Review the scan tool freeze frame data. If possible, try to duplicate the conditions under which the DTC set.
With the engine running at normal operating temperature, monitor the DRBIII(R) parameters related to the DTC while wiggling the wire harness. Look for parameter values to change and/or a DTC to set.
Turn the ignition off.
Visually inspect the related wire harness. Disconnect all the related harness connectors. Look for any chafed, pierced, pinched, partially broken wires and broken, bent, pushed out, or corroded terminals.
Perform a voltage drop test on the related circuits between the suspected faulty component and the PCM.

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.

Inspect and clean all PCM, engine, and chassis grounds that are related to the most current DTC.
If numerous trouble codes were set, use a wire schematic and look for any common ground or supply circuits.
For any relay DTC's, 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 filler cap.
For intermittent misfire DTC's, check for restrictions in the intake and exhaust system, proper installation of sensors, vacuum leaks, and binding components that are run by the accessory drive belt.
Use the scan tool to perform a system test if one applies to failing component.
A data recorder, and/or lab scope and an assistant should be used to help diagnose intermittent conditions.
If any problems were found during the above inspections, repair as necessary. Perform POWERTRAIN VERIFICATION TEST VER-5 under VERIFICATION TESTS. If no problems were found, test is complete.