Pontiac Firebird – Grand AM – Grand Prix – LeMans – Sunbird – Sunfire – Trans Sport (1992 – 1995) Trouble Code Info

Model Year Engine identification System
Firebird  3.1/5.0/5.7L 1992 VIN  position 8 = E/F/T/8 GM
Grand AM  2.3L 1992-95 VIN  position  8 = D/A/3 GM
Grand Prix 3.1/3.4L 1992-93 VIN  position  8 = T/M/X GM
LeMans  1.6L 1992-93 VIN  position  8 = 6 GM
Sunbird  2.0/3.1 L 1992-94 VIN  position 8 = H/T GM
Sunfire 2.2L 1995 VIN  position  8 = 4 GM
Sunfire 2.3L 1992-95 VIN  position 8 = D GM
Trans Sport 3.1L 1992-95 VIN  position 8 = D GM

General information

  • Refer to the front of this manual for general test conditions, terminology, detailed descriptions of wiring faults and a general trouble shooter for electrical and mechanical faults.
  • Malfunction indicator lamp (MIL) will illuminate if certain faults are recorded.
  • ECM operates in backup mode if sensors fail, to enable vehicle to be driven to repair shop.
  • Trouble codes can be displayed by the MIL or by using a Scan Tool connected to the data link connector (DLC).

Accessing

Models with data link connector (DLC) terminal B connected

  • Access data link connector (DLC).
  • Jump data link connector (DLC) terminals A and B 1.
  • Switch ignition ON. Do NOT start engine.
  • Count MIL flashes. Note trouble codes. Compare with trouble code table.
  • Firstly trouble code 12 will be displayed 3 times.
• Trouble codes consist of 2 groups, displayed as follows:
o First group indicates the ‘tens’ of the trouble code [2] [A].
o Second group indicates the ‘units’ of the trouble code [2] [C]·
o A short pause separates each group [2] [B].
o A long pause separates each trouble code [2] [D].
o For example: Trouble code 12 displayed [2]. Start of diagnosis.
• Each additional trouble code will now be displayed 3 times, in ascending order.
NOTE: If no additional trouble codes are stored, code 12 will continue to be displayed.
• Trouble codes can also be displayed by using a Scan Tool connected to the data link connector (DLC) 1.

Models without data link connector (DLC) terminal B connected

• Trouble codes can only be displayed by using a Scan Tool connected to the data link connector (DLC) 1 firebird1firebird2

Erasing

NOTE: Disconnecting battery ground lead may cause driveability problems until the engine management system relearns basic values.
  • Ensure ignition switched OFF.
  • Disconnect battery ground cable for 30 seconds.
  • Reconnect battery ground cable.
  • Repeat checking procedure to ensure no trouble codes remain in ECM fault memory.
NOTE: Disconnecting battery ground lead may also erase memory from electronic units, such as radio.
• Trouble codes can also be erased by using a Scan Tool connected to the data link connector (DLC).

Trouble code  identification

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 highllow Wiring, ECT sensor, ECM
15 Engine coolant temperature (ECT) sensor voltage high Wiring open circuit, ECT sensor, ECM
16 ~ System voltage highllow Wiring, battery, alternator
16 9 Crankshaft position (CKP) sensor, 2X referencesignal -circuit malfunction Wiring, ICM, ECM
17 Camshaft position (CMP) sensor -circuit malfunction Wiring, CMP sensor, mechanical fault, ECM
19 Crankshaft position (CKP) sensor, 7x/S8X signal -circuit malfunction Wiring, CKP sensor, ECM
21 Throttle position (TP) sensor -voltage highllow Wiring, 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 highllow 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 driverl output driver -circuit malfunction Wiring, ECM controlled components, ECM IiJ
27 Engine control module (ECM), quad driver/ output driver -circuit malfunction Wiring, ECM controlled components, ECM IiJ
28 Engine control module (ECM), quad driver/ output driver -circuit malfunction Wiring, ECM controlled components, ECM liJ
29 Engine control module (ECM), quad driver/ output driver -circuit malfunction Wiring, ECM controlled components, ECM liJ
31 Transmission range (TR) switch -malfunction Wiring, TR switch, ECM
32 Exhaust gas recirculation (EGR) solenoid Wiring, poor connections, EGR valve, ECM
33 Manifold absolute pressure (MAP) sensor voltage highllow Wiring, hose blocked/leaking, MAP sensor, ECM
34 Manifold absolute pressure (MAP) sensor voltage low Wiring open circuit/short circuit to ground, MAP sensor, ECM
35 Idle air control (lAC) valve Wiring, lAC valve, intake system leaking, fuel system, PCV valve, A/C system, mechanical fault,ECM
36 Crankshaft position (CKP) sensor, at crankshaft pulley -24X signal circuit malfunction Wiring, CKP sensor, ECM
39 Clutch pedal position (CPP) switch Wiring, incorrectly adjusted, CPP switch, ECM
41 D Engine control module (ECM), programming -malfunction ECM incorrect programming, ECM failure
41 19 Crankshaft position (CKP) sensor, 1X reference signal -circuit malfunction Wiring, ICM, 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
46 Immobilizer system, code -malfunction Incorrect key, ECM
51 Engine control module (ECM), PROM -malfunction Poor connections, incorrect programming, ECM
52 Engine control module (ECM) -malfunction ECM
53 System voltage high Alternator
54 Fuel pump circuit -voltage low Wiring open circuit/short circuit to ground, fuel pump relay, engine oil pressure warning lamp/fuel pump switch
550 Engine control module (ECM) -malfunction ECM
55 f) Engine control module (ECM), fuel lean monitor Fuel filterllines blocked, fuel contamination
61 Oxygen sensor (028) malfunction 25
62 Transmission gear switch, signal -circuitmalfunction Wiring open circuit/short circuit to ground, 2nd gear switch, 3rd gear switch, ECM
65 Injector(s) -circuit malfunction Wiring, injector(s)
66 A/C refrigerant pressure sensor -voltage low Wiring open circuit/short circuit to ground, A/C refrigerant pressure sensor, ECM
70 A/C refrigerant pressure sensor -voltage high Wiring open circuit/short circuit to positive, A/C refrigerant pressure sensor, ECM
72 CAN data bus, ECM to instrumentation control module -lost communication Wiring, poor connections, instrumentation control module, ECM
75 Exhaust gas recirculation (EGR) solenoid 1 circuit malfunction Wiring, EGR valve, ECM
76 Exhaust gas recirculation (EGR) solenoid 2 circuitmalfunction Wiring, EGR valve, ECM
77 Exhaust gas recirculation (EGR) solenoid 3 circuit malfunction Wiring, EGR valve, ECM
79 Vehicle speed sensor (V88) -voltage high Wiring, V55, ECM
80 Vehicle speed sensor (VSS) -voltage low Wiring, VSS, ECM
81 Brake pedal position (BPP) switch, TCC circuitmalfunction Wiring, BPP switch, ECM
82 Crankshaft position (CKP) sensor, in cylinderblock -3X signal circuit malfunction Wiring open circuit/short circuit to ground, CKP sensor, ICM
85 Engine control module (ECM), PROM malfunction Poor connections, incorrect programming, ECM
86 Engine control module (ECM) -analogue/digital converter A/C refrigerant pressure sensor/knock sensor(KS)/engine coolant temperature (ECT) sensor/fuel pump monitor circuit short circuit to battery voltage
87 Engine control module (ECM), EEPROM -malfunction Poor connections, incorrect programming, ECM