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Trouble Code Identification

TROUBLE CODE IDENTIFICATION

Code System Affected (1) MIL In Normal Mode (1) MIL In Test Mode Probable Cause
12  RPM Signal ON N/A Distributor, Starter Or Circuit, ECM
13  RPM Signal (2) (3) Distributor Or Ckt., ECM
14  Ignition Signal ON N/A Ignitor Or Ckt. To ECM, ECM
16 (4) A/T Cntl. Signal ON N/A ECM Or Circuit
21 (5) O2 Sensor Signal ON ON O2 Sensor Or Circuit, ECM
22  Engine Coolant Temp. Sens Sgnl ON ON Engine Coolant Temperature Sensor Or Circuit, ECM
24  Intake Air Temp. Sensor Signal ON ON O2 Sensor Or Ckt., ECM
25  Lean Air/ Fuel Mixture ON ON Injector Or Ckt., O2 Sensor Or Ckt. Fuel Pressure, Ignition System, Vacuum Leak, Compression Pressure, ECM
26  Rich Air/ Fuel Mixture ON ON Injector Or Ckt., O2 Sensor Or Ckt. Fuel Pressure, Ignition System, Compression Pressure, ECM
27 (5) Sub-O2 Sensor Signal ON ON Sub-O2 Sensor Or Ckt., ECM
28  O2 Sensor Signal ON ON O2 Sensor Or Circuit, ECM
31  Airflow Meter ON N/A Airflow Meter Or Ckt., ECM
35  BARO Sensor ON ON ECM
41  Throttle Position Sensor Signal ON ON Throttle Position Sensor Or Circuit, ECM
42  Vehicle Sensor Signal OFF OFF Vehicle Speed Sensor Or Circuit, ECM
43  Starter Signal N/A OFF Starter Signal Circuit Starter Relay, Ignition Switch Or Circuit, ECM
47 (6) Sub-Thrtl Position Sensor Signal OFF ON Sub-Throttle Position Sensor Or Circuit, ECM
51  Switch Condition Signal N/A OFF A/C Switch Circuit, Park/Neutral Switch Or Circuit, TPS Or Circuit, ECM
52  Knock Sensor Signal ON N/A Front Knock Sensor Or Circuit, ECM
53  Knock Control Signal ON N/A ECM
55  Knock Sensor Signal ON N/A Rear Knock Sensor Or Circuit, ECM
71  EGR System Malfunc. ON ON EGR System, EGR Temperature Sensor Or Circuit EGR-VSV, ECM
78  Fuel Pump Control Signal OFF ON Fuel Pump ECU Or Ckt., Fuel Pump, ECM Power Source Or ECM
(1) ON indicates MIL on instrument panel will be illuminated. N/A indicates item is not included in malfunction diagnosis when using this mode. OFF indicates MIL on instrument panel will not be illuminated even if malfunction is detected.
(2) The MIL will be illuminated only if no "NE" signal is sent to ECM with engine at approximately 1000 RPM .
(3) The MIL will be illuminated only if "NE" signal does not pulse 12 times to ECM during interval between "G1" and "G2" pulses.
(4) Applies only to models with electronic controlled automatic transmission.
(5) Applies to Calif. models only.
(6) Applies to models with traction control only.