Engine Controls - Tests W/Codes: Summary

If no hard fault codes are present (or only pass codes), driveability symptoms exist or intermittent codes exist, proceed to TESTS W/O CODES article in the ENGINE PERFORMANCE Section for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.

NOTE: To determine a common cause for a code to be set, see CODE DIAGNOSTIC HINTS table.

CODE DIAGNOSTIC HINTS

Code

Diagnostic Hints

Momentary Interruption Of Power Supply To ECU

No "G" or "NE" (RPM) Ignition Signal To ECU Within 2 Seconds After Engine Is Cranked

No "NE" (RPM) Ignition Signal To ECU When Engine Speed Is Greater Than Approximately 1000 RPM

No "IGF" Ignition Signal To ECU From Ignitor Several Times In Succession

Fault In Transmission/Transaxle ECU

Defective O2 Sensor, Open Or Short Circuit In O2 Sensor Signal

Open Or Short Circuit In Coolant Temp. Sensor Signal

Open Or Short Circuit In Intake Air Temp. Sensor Signal

Lean Signal Sent By O2 Sensor For Several Seconds

Rich Signal Sent By O2 Sensor For Several Seconds

Open Or Short Circuit In Sub-O2 Sensor Signal

Defective No. 2 O2 Sensor, Open Or Short Circuit In No. 2 O2 Sensor Signal

Open Or Short Circuit In Airflow Meter Or Vacuum Sensor Signal

Open Or Short Circuit Between Airflow Meter Terminals

Turbocharger Pressure Is Abnormal

Open Or Short Circuit In Turbocharger Pressure Sensor Or High Altitude Compensator Signal

Open Or Short Circuit In Throttle Position Sensor Signal

No "SPD" Signal From Vehicle Speed Sensor For Several Seconds With Engine Speed Approximately 2500-5500 RPM

No "STA" Signal To ECU Until Engine Reaches 800 RPM With Vehicle Not Moving

⁽¹⁾ Problem In One Of 3 Circuits Monitored By ECU

Open Or Short Circuit In Knock Sensor Signal

Knock Control In ECU Is Faulty

EGR Gas Below Predetermined Level During EGR Control

⁽¹⁾	The throttle position sensor, neutral safety switch and A/C Signal circuits are monitored.