GM S-Series Pick-ups and SUV's 1994-1999 Repair Guide

Clearing Codes

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Stored fault codes may be erased from memory at any time by removing power from the VCM for at least 30 seconds. It may be necessary to clear stored codes during diagnosis to check for any recurrence during a test drive, but the stored codes must be written down when retrieved. The codes may still be required for subsequent troubleshooting. Whenever a repair is complete, the stored codes must be erased and the vehicle test driven to confirm correct operation and repair.


WARNING
The ignition switch must be OFF any time power is disconnected or restored to the VCM. Severe damage may result if this precaution is not observed.

Depending on the electrical distribution of the particular vehicle, power to the VCM may be disconnected by removing the VCM fuse in the fusebox, disconnecting the in-line fuse holder near the positive battery terminal or disconnecting the VCM power lead at the battery terminal. Disconnecting the negative battery cable to clear codes is not recommended as this will also clear other memory data in the vehicle such as radio presets.

The following are the codes for the 1994-95 models with the OBD I and OBD II systems.

See Figure 1 through 6



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Fig. Fig. 1: DTC chart for 1994 ECM models



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Fig. Fig. 2: DTC chart for 1994 PCM models



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Fig. Fig. 3: DTC chart for 1994-95 VCM models



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Fig. Fig. 4: DTC chart for 1995 PCM models



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Fig. Fig. 5: DTC chart for 1995 VCM-A models



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Fig. Fig. 6: DTC chart for 1995 VCM-A models

The following is a list of trouble codes for the 1996-99 models with the OBD II system

P0101 Mass or Volume Air Flow Circuit Range/Performance Problem P0102 Mass or Volume Air Flow Circuit Low Input P0103 Mass or Volume Air Flow Circuit High Input P0106 Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance Problem P0107 Manifold Absolute Pressure/Barometric Pressure Circuit Low Input P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High Input P0112 Intake Air Temperature Circuit Low Input P0113 Intake Air Temperature Circuit High Input P0117 Engine Coolant Temperature Circuit Low Input P0118 Engine Coolant Temperature Circuit High Input P0121 Throttle/Pedal Position Sensor/Switch "A" Circuit Range/Performance Problem P0122 Throttle/Pedal Position Sensor/Switch "A" Circuit Low Input P0123 Throttle/Pedal Position Sensor/Switch "A" Circuit High Input P0125 Insufficient Coolant Temperature For Closed Loop Fuel Control P0131 O2 Sensor Circuit Low Voltage (Bank no. 1 Sensor no. 1) P0132 O2 Sensor Circuit High Voltage (Bank no. 1 Sensor no. 1) P0133 O2 Sensor Circuit Slow Response (Bank no. 1 Sensor no. 1) P0134 O2 Sensor Circuit No Activity Detected (Bank no. 1 Sensor no. 1) P0135 O2 Sensor Heater Circuit Malfunction (Bank no. 1 Sensor no. 1) P0137 O2 Sensor Circuit Low Voltage (Bank no. 1 Sensor no. 2) P0138 O2 Sensor Circuit High Voltage (Bank no. 1 Sensor no. 2) P0139 O2 Sensor Circuit Slow Response (Bank no. 1 Sensor no. 2) P0140 O2 Sensor Circuit No Activity Detected (Bank no. 1 Sensor no. 2) P0141 O2 Sensor Heater Circuit Malfunction (Bank no. 1 Sensor no. 2) P0143 O2 Sensor Circuit Low Voltage (Bank no. 1 Sensor no. 3) P0144 O2 Sensor Circuit High Voltage (Bank no. 1 Sensor no. 3) P0146 O2 Sensor Circuit No Activity Detected (Bank no. 1 Sensor no. 3) P0147 O2 Sensor Heater Circuit Malfunction (Bank no. 1 Sensor no. 3) P0151 O2 Sensor Circuit Low Voltage (Bank no. 2 Sensor no. 1) P0152 O2 Sensor Circuit High Voltage (Bank no. 2 Sensor no. 1) P0153 O2 Sensor Circuit Slow Response (Bank no. 2 Sensor no. 1) P0154 O2 Sensor Circuit No Activity Detected (Bank no. 2 Sensor no. 1) P0155 O2 Sensor Heater Circuit Malfunction (Bank no. 2 Sensor no. 1) P0171 System Too Lean (Bank no. 1) P0172 System Too Rich (Bank no. 1) P0174 System Too Lean (Bank no. 2) P0175 System Too Rich (Bank no. 2) P0200 Injector Circuit Malfunction P0300 Random/Multiple Cylinder Misfire Detected P0301 Cylinder no. 1-Misfire Detected P0302 Cylinder no. 2-Misfire Detected P0303 Cylinder no. 3-Misfire Detected P0304 Cylinder no. 4-Misfire Detected P0305 Cylinder no. 5-Misfire Detected P0306 Cylinder no. 6-Misfire Detected P0325 Knock Sensor no. 1-Circuit Malfunction (Bank no. 1 or Single Sensor) P0327 Knock Sensor no. 1-Circuit Low Input (Bank no. 1 or Single Sensor) P0334 Knock Sensor no. 2-Circuit Input Intermittent (Bank no. 2) P0335 Crankshaft Position Sensor "A" Circuit Malfunction P0336 Crankshaft Position Sensor "A" Circuit Range/Performance P0337 Crankshaft Position Sensor "A" Circuit Low Input P0338 Crankshaft Position Sensor "A" Circuit High Input P0339 Crankshaft Position Sensor "A" Circuit Intermittent P0340 Camshaft Position Sensor Circuit Malfunction P0341 Camshaft Position Sensor Circuit Range/Performance P0342 Camshaft Position Sensor Circuit Low Input P0401 Exhaust Gas Recirculation Flow Insufficient Detected P0404 Exhaust Gas Recirculation Circuit Range/Performance P0405 Exhaust Gas Recirculation Sensor "A" Circuit Low P0420 Catalyst System Efficiency Below Threshold (Bank no. 1) P0440 Evaporative Emission Control System Malfunction P0442 Evaporative Emission Control System Leak Detected (Small Leak) P0446 Evaporative Emission Control System Vent Control Circuit Malfunction P0452 Evaporative Emission Control System Pressure Sensor Low Input P0453 Evaporative Emission Control System Pressure Sensor High Input P0460 Fuel Level Sensor Circuit Malfunction P0461 Fuel Level Sensor Circuit Range/Performance P0462 Fuel Level Sensor Circuit Low Input P0463 Fuel Level Sensor Circuit High Input P0500 Vehicle Speed Sensor Malfunction P0502 Vehicle Speed Sensor Circuit Low Input P0506 Idle Control System RPM Lower Than Expected P0507 Idle Control System RPM Higher Than Expected P0530 A/C Refrigerant Pressure Sensor Circuit Malfunction P0562 System Voltage Low P0563 System Voltage High P0600 Serial Communication Link Malfunction P0601 Internal Control Module Memory Check Sum Error P0602 Control Module Programming Error P0603 Internal Control Module Keep Alive Memory (KAM) Error P0604 Internal Control Module Random Access Memory (RAM) Error P0605 Internal Control Module Read Only Memory (ROM) Error P0704 Clutch Switch Input Circuit Malfunction P0705 Transmission Range Sensor Circuit Malfunction (PRNDL Input) P1106 MAP Sensor Voltage Intermittently High P1107 MAP Sensor Voltage Intermittently Low P1111 IAT Sensor Circuit Intermittent High Voltage P1112 IAT Sensor Circuit Intermittent Low Voltage P1114 ECT Sensor Circuit Intermittent Low Voltage P1115 ECT Sensor Circuit Intermittent High Voltage P1121 TP Sensor Voltage Intermittently High P1122 TP Sensor Voltage Intermittently Low P1133 HO 2 S Insufficient Switching Bank #1, Sensor #1 P1134 HO 2 S Transition Time Ratio Bank #1, Sensor #1 P1153 HO 2 S Insufficient Switching Sensor Bank #2, Sensor #1 P1154 HO 2 S Transition Time Ratio Bank #2, Sensor #1 P1171 Fuel system lean during acceleration P1336 CKP system variation not learned P1345 Crankshaft/Camshaft (CKP/CMP) Correlation P1351 Ignition Control (IC) Circuit High Voltage P1361 Ignition Control (IC) Circuit Not Toggling P1361 Ignition Control (IC) Circuit Low Voltage P1374 3X Reference circuit P1380 Electronic Brake Control Module (EBCM) DTC Detected Rough Road Data Unusable P1381 Misfire Detected, No EBCM/PCM/VCM Serial Data P1404 EGR valve closed pintle position P1406 EGR Pintle Position Circuit Fault P1441 EVAP Control System Flow During Non-Purge P1508 IAC System Low RPM P1509 IAC System High RPM P1520 PNP Circuit P1621 PCM memory performance P1626 Theft deterrent system fuel enable CKT P1631 Theft deterrent password incorrect P1632 Theft deterrent system fuel disabled U1000 No class 2 communication learned U1026 Loss of ATCM communication U1041 Loss of EBCM communication U1064 Loss of TBC/BCM and/or VTD communication

 
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