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Symptom #2 - Check engine indicator illuminates

Description

• Check engine indicator is illuminated incorrectly.

Possible Causes

• Check engine indicator illuminates for emission-related concern (DTC is stored in ECU).
• Short to ground circuit between check engine indicator and ECU.

Note: If the check engine indicator blinks at a steady rate, a misfire condition could possibly exist.

Diagnostic Procedure

1.  Scan for DTCs.  Any trouble codes present?

• Yes - Go to appropriate DTC test.
• No - Inspect for short to ground circuit between check engine indicator and ECU and go to step #2.

2.  If circuit is now okay, return to the Symptom Troubleshooting index to service any additional symptoms.  Is vehicle repaired?

• Yes - Troubleshooting completed.
• No - Replace ECU.