GM GM 94-95 3.1L VIN M Trouble Code Info

GM

94-95 3.1L VIN M
Flash Code Fault Location Probable Cause
11 Malfunction indicator lamp (MIL) – cirucit malfunction Wiring open circuit/short circuit to ground, MIL, supply wire, ECM
12 Start of diagnosis No engine speed (RPM) signal received)
13 Oxygen sensor voltage stays between 0.35 and 0.55 volts for 30 seconds when the TPS signal was above 3%. The engine had been operating in a closed loop with an engine temperature above 149° F. Wiring open circuit, O2S/HO2S, ECM
14 Coolant temperature sensor signal indicates a temperature of over 275° F after the engine had been running for at least 10 seconds. Wiring short circuit to ground, ECT sensor, ECM
15 Coolant temperature sensor signal indicates a temperature colder than -38° F for 2 seconds. Wiring open circuit to ground, ECT sensor, ECM
16 Charging system voltage was below 8 volts for 5 seconds when engine speed was above 1000 RPM. Wiring, alternator, ECM
17 PCM did not detect any cam reference pulses for 3 seconds while engine was running. Wiring open circuit/short circuit to ground/short circuit to positive, mechanical fault, CMP sensor, ECM
18 Injector(s) – circuit malfunction Wiring open circuit/short circuit to ground, supply wire, injectors, ECM
19 7X reference – circuit malfunction Wiring, mechanical fault, CKP sensor, PROM, ECM
21 TPS voltage was above 3.8 volts for 5 seconds when engine was running above 600 RPM. Wiring open circuit/short circuit to positive, TP sensor, ECM
22 TPS voltage was under 0.2 volts for 3 seconds when the engine was running at 400 RPM or more. Wiring open circuit/short circuit to ground, TP sensor, ECM
23 Inlet air temperature sensor signal showed an air temperature of -36° F for 4 minutes. Wiring open circuit, IAT sensor, ECM
24 Vehicle speed sensor signal showed less than 5 MPH for 4 seconds when engine speed was greater than 3000 RPM and transmission was not in park or neutral. Wiring open circuit/short circuit, PROM, VSS, ECM
25 Inlet air temperature sensor signal showed an air temperature over 297 F for 5 seconds when I vehicle speed was greater than 1 MPH. Wiring short circuit to ground, IAT sensor, ECM
26 Engine control module quad driver/output driver Wiring open circuit/short circuit to ground/short circuit to positive, ECM controlled components, ECM * (see below for additional details)
27 Exhaust gas recirculation (EGR) vacuum control – circuit malfunction Wiring open/short circuit to ground/short circuit to positive, EGR valve, ECM
28 Transaxle range switch had incorrect signal for 10 seconds. Wiring open circuit/short circuit to ground, transmission range switch, ECM
29 Secondary air injection (AIR) system Wiring open circuit/short circuit to ground/short circuit to positive, AIR valve relay, ECM
31 Park/neutral position (PNP) switch Wiring open circuit/short circuit to ground, incorrectly adjusted, PNP switch, ECM
32 Digital EGR calibrated response in manifold pressure was not seen by ECM. Wiring open circuit/short circuit to ground, exhaust system blocked, EGR valve, ECM
33 MAP sensor signal voltage was too high (low vacuum) for 4 seconds when throttle angle was between 3% and 30% and held steady. Wiring open circuit/short circuit to positive, hose blocked/leaking, MAP sensor, ECM
34 MAP sensor signal voltage was too low (high vacuum) for 2.5 seconds when engine speed was above 500 RPM. Wiring open circuit/short circuit to ground, MAP sensor, ECM
35 Idle speed was either above or below desired idle by 350 RPM for 50 seconds. Wiring open circuit/short circuit to ground/short circuit to positive, intake system leaking, mechanical fault, IAC valve, ECM
36 PCM did not detect 6 or more consecutive 24X (crank reference) pulses. Wiring open circuit/short circuit to ground, CKP sensor, ECM
37 PCM did not receive the TCC brake signal 4 consecutive times when vehicle speed went from above 35 MPH (for at least 10 seconds) to 0 MPH. Wiring open circuit/short circuit to ground/short circuit to positive, TCC brake switch, ECM
38 Brake pedal position (BPP) switch Wiring open circuit/short circuit to ground/short circuit to positive, BPP switch, BPP switch incorrectly adjusted, ECM
39 Torque converter clutch (TCC) – circuit malfunction Wiring open circuit, BPP switch, TCC solenoid, TCC switch, 3rd gear switch, mechanical fault, ECM
41 BUICK Skylark Camshaft position (CMP) sensor Wiring open circuit/short circuit to ground, CMP sensor, ICM, ECM
41 The EST signal was present when the circuit should have been grounded by the ignition module when it received bypass voltage under 1 volt. Wiring, poor connections, ICM, ECM
42 The EST signal did not change when the ECM applied bypass voltage to the ignition module. Wiring open circuit/short circuit to ground, ICM, ECM
43 The ECM detected knock sensor voltage above 4.6 volts or below 0.84 volts for 10 seconds during hard acceleration with engine speed between 3400 and 4400 RPM. Wiring open circuit/short circuit to ground/short to positive, KS, PROM, ECM
44 Oxygen sensor voltage was under 0.25 volts for 60 seconds of closed loop operation. Wiring short circuit to ground, fuel pressure low, fuel contamination, exhaust system leaking, O2S/HO2S, ECM
45 Oxygen sensor voltage was over 0.75 volts for 60 seconds of closed loop operation. Fuel pressure high, injector(s) leaking, shield wiring open circuit, O2S contamination, EVAP canister purge valve, TP sensor, MAP sensor, EGR system, excessive fuel in engine oil, ECM
46 Immobilizer control module – fuel enable signal Incorrect ignition key, wiring open circuit/short circuit to ground, immobilizer control module, ECM
47 Body control module (BCM), CAN data bus – communication malfunction Wiring, PROM, BCM
48 Mass air flow (MAF) sensor – circuit malfunction Wiring open circuit/short circuit to ground/short circuit to positive, MAF sensor, ECM
50 System voltage low Wiring open circuit/short circuit to ground, alternator, ECM
51 PROM error. Insecure PROM, incorrect PROM, ECM
53 Charging system voltage was greater than 16.5 volts. Alternator, ECM
54 Fuel pump voltage was above 14 volts or less than 7 volts for 3 seconds. Wiring open circuit/short circuit to ground, fuel pump relay, fuel pump, engine oil pressure warning lamp switch, ECM
55 Engine control module (ECM) Ground wiring open circuit, insecure PROM, ECM
58 Immobilizer control module – fuel enable signal Incorrect ignition key, wiring open circuit/short circuit to ground/short circuit to positive, immobilizer control module, ECM
59 Transmission fluid temperature (TFT) sensor – low temperature indicated Wiring open circuit, TFT sensor, ECM
61 Cruise control vent solenoid Wiring open circuit/short circuit to ground/short circuit to positive, cruise control servo, ECM
62 Cruise control vacuum solenoid Wiring open circuit/short circuit to ground/short circuit to positive, cruise control servo, ECM
63 Heated oxygen sensor (HO2S) bank 2 – open circuit Wiring open circuit/short circuit to ground/short circuit to positive, HO2S, HO2S contamination, ECM
64 Heated oxygen sensor (HO2S) bank 2 – mixture lean Wiring short circuit to ground, injector(s) blocked, fuel contamination, fuel pressure low, exhaust system leaking, ECM
65 Cruise control servo position sensor – circuit malfunction Wiring open circuit/short circuit to ground/short circuit to positive, cruise control servo, ECM
66 A/C refrigerant pressure sensor – low pressure Wiring open circuit, A/C refrigerant pressure sensor, ECM
67 Cruise control switch – circuit malfunction Wiring open circuit/short circuit to positive, cruise control switch, brake pedal vacuum valve, ECM
68 Cruise control servo – servo position sensor high Hoses blocked, brake pedal vacuum valve, cruise control servo, cruise control cable binding
69 A/C compressor clutch relay – circuit malfunction Wiring open circuit, A/C compressor clutch relay, ECM
70 A/C refrigerant pressure sensor – high pressure Wiring open circuit/short circuit to positive, A/C refrigerant pressure sensor, ECM
72 Vehicle speed sensor indicated a sudden change in speed of more than 33 MPH in 2 seconds when vehicle was in gear. Wiring open circuit/short circuit to ground, VSS, ECM
73 Pressure control solenoid – circuit malfunction Wiring open circuit/short circuit to ground/short to positive, ECM
75 Digital EGR solenoid 1 failed 3 consecutive times. Engine speed was between 1400 and 2000 RPM when throttle angle was 0% and the MAP sensor showed high manifold vacuum. Wiring open circuit/short circuit to ground, supply wire, EGR valve, ECM
76 Digital EGR solenoid 2 failed 3 consecutive times. Engine speed was between 1400 and 2000 RPM when throttle angle was 0% and the MAP sensor showed high manifold vacuum. Wiring open circuit/short circuit to ground, supply wire, EGR valve, ECM
77 Digital EGR solenoid 3 failed 3 consecutive times. Engine speed was between 1400 and 2000 RPM when throttle angle was 0% and the MAP sensor showed high manifold vacuum. Wiring open circuit/short circuit to ground, supply wire, EGR valve, ECM
78 Engine coolant blower motor relay 2 – circuit malfunction Wiring open circuit/short circuit to ground/short circuit to positive, engine coolant blower motor relay, ECM
79 Transmission fluid – overtemp Wiring open circuit/short circuit to ground, TFT sensor, ECM
80 Transmission component – slipping Wiring open circuit/short circuit to ground/short circuit to positive, TR pressure switch, transmission mechanical fault, ECM
81 Transmission shift solenoid (SS), 2nd-3rd – circuit malfunction Wiring open circuit/short circuit to ground, shift solenoid, ECM
82 3X reference pulses were not detected by PCM during cranking. Wiring open circuit/short circuit to ground, CKP sensor, ICM, ECM
83 Torque converter clutch (TCC) solenoid, pulse width modulated – circuit malfunction Wiring open circuit/short circuit to ground/short circuit to positive, CKP sensor, TCC solenoid, ECM
84 Transmission shift solenoid (SS), 3rd-2nd – circuit malfunction Wiring open circuit/short circuit to ground, shift solenoid, ECM
85 Engine control module (ECM) – PROM Insecure PROM, incorrect PROM, ECM
86 ECM analog/digital – signal error Wiring short to positive, A/C refrigerant pressure sensor, KS, ECT sensor, other DTC codes
87 Engine control module (ECM) – EEPROM Insecure EEPROM, incorrect EEPROM, ECM
90 TCC solenoid voltage stayed high for 2 seconds after it was turned ON by the PCM, or the TCC solenoid voltage was 0 volts for 2 seconds after it was turned OFF by the PCM. Wiring open circuit/short circuit to ground, TCC solenoid, ECM
95 Change oil lamp – circuit malfunction Wiring open circuit/short circuit to ground/short circuit to positive, instrument panel, engine oil life lamp bulb, ECM
96 Transmission system – voltage low Wiring open circuit, alternator, ECM
97 Vehicle speed sensor (VSS) – circuit malfunction Wiring open circuit/short circuit to ground/short circuit to positive, VSS, ECM
98 Invalid ECM program ECM
99 Invalid ECM program ECM
* Depending on model, year and equipment level, the following components may be connected to this circuit. Use of the vehicle wiring diagram is recommended to confirm which components are fitted.
A/C compressor clutch relay Exhaust gas recirculation (EGR) solenoid
A/C condenser blower motor relay Malfunction indicator lamp (MIL)
Engine coolant blower motor relay Transmission shift warning light (MT)
Engine coolant ‘hot’ warning lamp Torque converter clutch (TCC) solenoid
Evaporative emission (EVAP) canister purge Transmission shift solenoids (SS)