- Intermittent Malfunctions

Problem may or may not turn "ON" the "CHECK ENGINE" light, or store a code. Most intermittent problems are caused by faulty electrical connections or damaged wiring.

Perform a visual check of suspected circuits.

- Poor or loose connection of connectors.

- Misrouted wiring.

- Inspect any loose connector for corrosion or terminal loose in cavity.

- Damaged or poorly formed terminals.

- Poor terminal to wire connection, broken wire strands, insulation pinched in terminal.

In the case of an "intermittent" problem, the "CHECK ENGINE" light will remain "ON" as long as the trouble exists and will turn "OFF" when the system returns to normal. Except in the case of EGR intermittents. EGR intermittents will cause the light to remain "ON" until the ignition switch is turned "OFF." Corresponding trouble code will be stored in the memory of the ECM until the battery voltage to the ECM has been removed, except in the case of the ESA model for Code 41, the ignition circuit. Code 41 does not store in the memory of the ECM for the ESA Metro. When the engine fails to start, crank the engine, and then ground the diagnostic switch terminal with the ignition "ON," to read codes. When unexpected codes appear during the code reading process, one can assume that these codes were set by an intermittent malfunction and could be helpful in diagnosing the system. An intermittent code may or may not reset. If it is an intermittent failure, a Diagnostic Trouble Code Chart is not used. A physical inspection of the applicable sub-system most often will resolve the problem.