GM GM 92-93 3.8L Bonneville, 3.3 L Grand AM, 3.8L Transport Trouble Code Info

GM

Various Models
Flash code Fault location Probable cause
12 Start of diagnosis No engine speed (RPM) signal received
13 Oxygen sensor (02S)/heated oxygen sensor (H02S) Wiring open circuit, 02S/H02S, ECM
14 Engine coolant temperature (ECT) sensor -voltage low Wiring short circuit to ground, ECT sensor, ECM
15 Engine coolant temperature (ECT) sensor -voltage high Wiring open circuit, ECT sensor, ECM
16 System voltage -high/low Wiring, battery, alternator
17 Ignition control system, reference signal -circuit malfunction Wiring, poor connections, ICM, ECM
18 Camshaft position (CMP) sensor – circuit malfunction Wiring, CMP sensor, mechanical fault, ECM
21 Throttle position (TP) sensor -voltage high Wiring open circuit/short circuit to positive, TP sensor, ECM
22 Throttle position (TP) sensor -voltage low Wiring open circuit/short circuit to ground, TP sensor, ECM
23 Intake air temperature (IAT) sensor -voltage high/low Wiring, IAT sensor, ECM
24 Vehicle speed sensor (VSS) -no signal Wiring, VSS, ECM
25 Intake air temperature (IAT) sensor -voltage low Wiring short circuit to ground, IAT sensor, ECM
26 Engine control module (ECM), quad driver/ output driver -circuit malfunction Wiring, ECM controlled components, ECM
27 Transmission gear switch, signal – circuit malfunction Wiring open circuit/short circuit to ground, 2nd gear switch, 3rd gear switch, ECM
28 Transmission gear switch, signal – circuit malfunction Wiring, TR switch, ECM
31 Park/neutral position (PNP) switch – malfunction Wiring, PNP switch, ECM
34 Mass airflow (MAF) sensor – voltage low Wiring, poor connections, MAF sensor, ECM
36 Transmission Shift solenoid (SS) – circuit malfunction Wiring, SS, ECM
38 Brake pedal position (BPP) switch, torque converter clutch (TCC) Wiring, incorrectly adjusted, BPP switch, ECM
39 Torque converter clutch (TCC) – slipping Wiring, TCC solenoid, transmission mechanical fault, ECM
41 Camshaft position (CMP) sensor – circuit malfunction Wiring, CMP sensor, mechanical fault, ECM
42 Ignition control, timing signal -circuit malfunction Wiring, poor connections, ICM, ECM
43 Knock sensor (KS) -circuit malfunction Wiring, KS, ECM
44 Oxygen sensor (02S)/heated oxygen sensor (H02S) -mixture lean Wiring open circuit/short circuit to ground, injector(s) blocked, fuel contamination, fuel pressure low, exhaust system leaking, 02S/H02S, ECM
45 Oxygen sensor (02S)/heated oxygen sensor (H02S) -mixture rich Wiring open circuit, fuel pressure high, injector(s) leaking, 02S/H02S, EVAP purge valve, TP sensor, EGR system, ECM
48 Misfire detected Ignition system, fuel system, O2S, engine mechanical fault
51 Engine control module (ECM), PROM -malfunction Poor connections, incorrect programming, ECM
53 Exhaust gas recirculation (EGR) valve solenoid 1 Wiring open circuit/short circuit to ground, supply wire, EGR valve, ECM
54 Exhaust gas recirculation (EGR) valve solenoid 2 Wiring open circuit/short circuit to ground, supply wire, EGR valve, ECM
55 Exhaust gas recirculation (EGR) valve solenoid 3 Wiring open circuit/short circuit to ground, supply wire, EGR valve, ECM
56 Engine control module (ECM), quad driver/ output driver -circuit malfunction Wiring, ECM controlled components, ECM
61 Cruise control vent solenoid – circuit malfunction Wiring, solenoid valve
62 Cruise control vacuum solenoid -circuit malfunction Wiring, solenoid valve
63 Cruise control system – performance low Wiring, poor connections, accelerator cable sticking
65 Cruise control servo position sensor – circuit malfunction Wiring, poor connections, servo position sensor
66 A/C refrigerant pressure sensor -voltage low Incorrect refrigerant charge, wiring, A/C refrigerant pressure sensor, ECM
67 Cruise control master switch -circuit malfunction Wiring, poor connections, cruise control master switch
68 Cruise control system – performance high Wiring, poor connections, accelerator cable sticking
69 A/C refrigerant pressure switch, engine coolant blower motors – circuit malfunction Wiring open circuit, A/C refrigerant pressure switch, ECM
99 Cruise control system – engine management has operated in limited power mode Accelerator cable sticking, brake vacuum release valve, cruise control actuator