Intermittent Problem Diagnosis

Intermittent fault testing requires duplicating circuit or component failure to identify the problem. These procedures may lead to PCM setting a DTC which may help in diagnosis. To reproduce conditions creating an intermittent fault, use the following methods:

• Lightly vibrate component.
• Heat component.
• Wiggle or bend wiring harness.
• Spray component with water.
• Remove/apply vacuum source.

Monitor circuit/component voltage or resistance while simulating intermittent. If engine is running, monitor for self-diagnostic DTCs. See QUICK TEST in SELF-DIAGNOSTICS - 7.3L DIESEL article. Use test results to identify a faulty component or circuit.