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Trouble Code Identification

TROUBLE CODE IDENTIFICATION

Code System Affected (1) Normal Mode (2) Test Mode Probable Cause
12  RPM Signal ON   Distributor, Starter Or Circuit, ECM
13  RPM Signal ON   Distributor Or Circuit, ECM
14  Ignition Signal ON   Ignitor Or Circuit To ECM, ECM
21  Oxygen Sensor Signal ON   Oxygen Sensor Or Circuit, ECM
22  Engine Coolant Temperature Sensor Signal ON   Engine Coolant Temp. Sensor Or Circuit, ECM
24  Intake Air Temperature Sensor Signal ON (3)   Intake Air Temp. Sensor Or Circuit, ECM
25  Lean Air/Fuel Mixture ON   Loose Ground, Injector Or Circuit, Oxygen Sensor Or Circuit, Fuel Pressure, Ignition System, Engine Coolant Temp. Sensor, MAP Sensor, ECM
26 (4) Rich Air/Fuel Mixture ON   Loose Ground, Injector Or Circuit, Oxygen Sensor Or Circuit, Fuel Pressure, Engine Coolant Temp. Sensor, MAP Sensor, Compression Pressure, ECM
31  Vacuum Sensor Signal ON   MAP Sensor Or Circuit, ECM
41  Throttle Position Sensor Signal ON (3)   Throttle Position Sensor Or Circuit, ECM
42  Vehicle Speed Sensor Signal OFF   Vehicle Speed Sensor Or Circuit, ECM
43  Starter Signal OFF   Starter Signal Circuit, Ignition Switch Or Circuit, ECM
51  Switch Signal OFF   A/C Switch Circuit, Park/Neutral Switch Or Circuit, TPS Or Circuit, ECM
71 (4) EGR System Malfunction ON   EGR System, EGR Temp. Sensor Or Circuit, EGR-VSV, ECM
(1) ON indicates MIL on instrument panel will be illuminated. OFF indicates MIL on instrument panel will not be illuminated even if malfunction is detected.
(2) Test mode is not used on this vehicle.
(3) The MIL will be illuminated on California vehicles only.
(4) Applies to California models only.