Intermittent Conditions

4L80-E AUTOMATIC TRANSMISSION

The Diagnostic Trouble Code (DTC) charts determine if there is a fault within the circuit. The fault must be present to locate the problem. If an intermittent condition occurs, a DTC will be stored in history status, but the circuit check will indicate a normal condition. Most intermittent conditions are usually a faulty connection or component. When diagnosing intermittents, thoroughly check the suspected circuits for:
- Poor terminal tension.
- Poor seating of connector halves.
- Poor terminal to wire connection.
- Improperly formed or damaged terminals.
- Improperly installed electrical options.
- Faulty Powertrain Control Module (PCM) power or ground connection.
- Intermittent short or open.
- Electrical system surges caused by a defective relay, solenoid, or switch. Normally these conditions will occur when the faulty component is operated.