Chevrolet Camaro 3.4L – Camaro 5.7L – Caprice 5.7L – Caprice Wagon 4.3L – Corvette 5.7L (OBD-II) OBD1 Codes

Model	Year	Engine identification	System
Camaro 3.4L	1993-95	VIN position 8 = S	GM
Camaro 5.7L	1993-94	VIN position 8 = P	GM
Caprice 5.7L	1993-95	VIN position 8 = P	GM
Caprice Wagon 4.3L	1993-95	VIN position 8 = W	GM
Corvette 5.7L (OBO-I)	1994	VIN position 8 = P	GM

General information

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.

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) 1.

Trouble code identification

Flash code	Fault location	Probable cause
11	Malfunction indicator lamp (MIL) -circuit malfunction	Wiring open circuit/short circuit to ground, MIL, ECM
12	Start of diagnosis	No engine speed (RPM) signal received
13	Oxygen sensor (02S), bank 2	Wiring open circuit, 025, ECM
13	Oxygen sensor (02S), bank 1	Wiring open circuit, 025, ECM
14	Engine coolant temperature (ECT) sensorvoltage 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 low	Wiring, alternator
16	Distributor ignition system, low resolution signal -circuit malfunction	Wiring, distributor, ECM
17	Camshaft position (CMP) sensor -circuit malfunction	Wiring, CMP sensor, mechanical fault, ECM
18	Injector(s) -circuit malfunction	Wiring, injector(s)
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	Wiring open circuit, 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	Evaporative emission (EVAP) canister purge valve -open!short circuit	Wiring, EVAP canister purge valve, ECM
26	Engine control module (ECM), quad driver! output driver -circuit malfunction	Wiring, ECM controlled components, ECM (!)
27	Engine control module (ECM), quad driver! output driver -circuit malfunction	Wiring, ECM controlled components, ECM (!)
27	Exhaust gas recirculation (EGR) solenoid	Wiring, poor connections, EGR valve, ECM
28	Engine control module (ECM), quad driverl output driver -circuit malfunction	Wiring, ECM controlled components, ECM m
28	Transmission range (TR) switch -malfunction	Wiring, TR switch, ECM
29	Secondary air injection (AIR) pump relay circuit malfunction	Wiring, AIR pump relay, ECM
32	Exhaust gas recirculation (EGR) solenoid	Wiring, poor connections, EGR valve, ECM
33	Manifold absolute pressure (MAP) sensor voltage high	Wiring short circuit to positive, 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 I	Wiring open circuit/short circuit to groundl shortcircuit to positive, 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
36	Distributor ignition system. high resolution signal -circuit malfunction	Wiring, distributor, ECM
37	Brake pedal position (BPP) switch for torque converter clutch (TCC)	Wiring, incorrectly adjusted, BPP switch, ECM
38	Brake pedal position (BPP) switch, torque converter clutch (TCC) -low voltage	Wiring open circuit, incorrectly adjusted, BPPswitch, ECM
39	Clutch pedal position (CPP) switch	Wiring, incorrectly adjusted, CPP switch, ECM
41	Ignition control. timing signal -circuit malfunction	Wiring, poor connections, ICM, ECM
42	Ignition control. bypass signal -circuit malfunction	Wiring, poor connections, ICM, ECM
43	Knock sensor (KS) -circuit malfunction	Wiring, KS, ECM
44	Oxygen sensor (02S). bank 2 -mixture lean	Wiring open circuit/short circuit to ground,injector(s) blocked, fuel contamination, fuel pressure low, exhaust system leaking, 025, ECM
44	Oxygen sensor (02S)/heated oxygen sensor(H02S). bank 1 -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), bank 2 -mixture rich	Wiring open circuit, fuel pressure high, injector(s) leaking, 025, EVAP purge valve, TP sensor, EGR system, ECM
450	Oxygen sensor (02S)/heated oxygen sensor(H02S). bank 1 -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, immobilizer control module, ECM
47	Knock control module, removable part in engine control module (ECM) -circuit malfunction	Wiring, poor connection, missing knock control module, ECM
48	Mass air flow (MAF) sensor -no signal	Wiring, poor connections, MAF sensor, ECM
50	System voltage low	Alternator
51	Engine control module (ECM), PROMmalfunction	Poor connections, incorrect programming, ECM
52	Engine oil temperature (EOT) sensor -voltagehigh	Wiring, EOT sensor, 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
55	Engine control module (ECM), fuel lean monitor	Fuel filterllines blocked, fuel contamination
58	Transmission fluid temperature (TFT) sensor voltage low	Wiring short circuit to ground, TFT sensor, ECM
59	Transmission fluid temperature (TFT) sensor voltage high	Wiring open circuit, TFT sensor, ECM
61	A/C system -performance	Refrigerant low, wiring, A/C refrigerant pressure sensor, A/C evaporator temperature sensor, ECM
62	Engine oil temperature (EOT) sensor -voltage low	Wiring, EOT sensor, ECM
63	Oxygen sensor (02S), bank 1	Wiring open circuit, 025, ECM
63	Oxygen sensor (02S)/heated oxygen sensor (H02S), bank 2	Wiring open circuit, 025/H025, ECM
64	Oxygen sensor (02S), bank 1 -mixture lean	Wiring open circuit/short circuit to ground,injector(s) blocked, fuel contamination, fuel pressure low, exhaust system leaking, 025, ECM ·
64	Oxygen sensor (02S)/heated oxygen sensor(H02S), bank 2 -mixture lean ,	Wiring open circuit/short circuit to ground,injector(s) blocked, fuel contamination, fuel pressure low, exhaust system leaking, 025/H025,ECM
65	Oxygen sensor (02S), bank 1 -mixture rich	Wiring open circuit, fuel pressure high, injector(s) leaking, 025, EVAP purge valve, TP sensor, EGR system, ECM
65	Oxygen sensor (02S)/heated oxygen sensor (H02S), bank 2 -mixture rich	Wiring open circuit, fuel pressure high, injector(s) leaking, 025/H025, EVAP purge valve, TP sensor, EGR system, ECM
66	A/C refrigerant pressure sensor -voltage low	Wiring open circuit/short circuit to ground, A/C refrigerant pressure sensor, ECM
67	A/C refrigerant pressure sensor -circuit malfunction	Wiring open circuit, A/C refrigerant pressuresensor, ECM
68	A/C compressor clutch relay -circuit malfunction	Wiring short circuit, A/C compressor clutch relay, ECM
69	A/C compressor clutch relay -circuit malfunction	Wiring open circuit, A/C compressor clutch relay, ECM
70	A/C refrigerant pressure sensor -voltage high	Wiring open circuit/short circuit to positive, ‘A/C refrigerant pressure sensor, ECM
71	A/C evaporator temperature sensor -voltage high	Wiring, poor connections, A/C evaporator temperature sensor
72	Vehicle speed sensor (V88) -circuit malfunction	Wiring, V55, ECM
73	A/C evaporator temperature sensor -voltage low	Wiring, poor connections, A/C evaporator temperature sensor
73	Transmission fluid pressure (TFP) control solenoid -circuit malfunction	Wiring, poor connection, TFP solenoid
74	Traction control system (TC5), active signal malfunction	Wiring short to ground, AB5ITC5, ECM
75	Exhaust gas recirculation (EGR) solenoid 1 circuit malfunction	Wiring, EGR valve, ECM
75	8ystem voltage low, engine control module (ECM)	Wiring, battery, alternator, ECM
76	Exhaust gas recirculation (EGR) solenoid 2 circuit malfunction	Wiring, EGR valve, ECM
77	Exhaust gas recirculation (EGR) solenoid 3 circuit malfunction	Wiring, EGR valve, ECM
77	Engine coolant blower motor relay -circuit malfunction	Wiring, engine coolant blower motor relay, ECM
78	Engine coolant blower motor relay 2 -circuit malfunction	Wiring open circuit/short circuit to groundl short circuit to positive, engine coolant blower motor relay, ECM
79	Transmission fluid temperature (TFT) high	Transmission mechanical fault, towing weight limit exceeded
80	Torque converter clutch (TCC) -slipping	Wiring, TCC solenoid, transmission mechanical fault, ECM
81	Brake pedal position (BPP) switch , torque converter clutch (TCC) -circuit malfunction	Wiring, BPP switch, ECM
81	Transmission shift solenoid (88), 2nd-3rd circuit malfunction	Wiring, 55, ECM
82	Crankshaft position (CKP) sensor, in cylinder block -3X signal circuit malfunction	Wiring open circuit/short circuit to ground, CKP sensor, ICM
82	Transmission shift solenoid (88), 1st-2nd -circuit malfunction	Wiring, 55, ECM
83	Reyerse gear inhibit solenoid -circuit malfunction	Wiring, reverse gear inhibit solenoid, ECM
83	Torque converter clutch (TCC) solenoid, pulse width modulated -circuit malfunction	Wiring open circuit/short circuit to groundl short circuit to pOSitive, TCC solenoid, ECM
84	Transmission 3rd-2nd control solenoid -circuit malfunction	Wiring, control solenoid, ECM
84	2nd-3rd gear inhibit relay -circuit malfunction	Wiring, inhibit relay, ECM
85	Engine control module (ECM), PROM -malfunction	Poor connections, incorrect programming, ECM
85	Torque converter clutch (TCC) solenoid -stuck ON	Wiring open circuit/short circuit to ground, transmission internal wiring, TCC solenoid, transmission mechanical fault, ECM
86	Engine control module (ECM) -analogue! digital converter	A/C refrigerant pressure sensor/KSI ECT sensor/fuel pump monitor circuit short circuit to battery voltage
87	Engine control module (ECM), EEPROMmalfunction	Poor connections, incorrect programming, ECM
90	Torque converter clutch (TCC) solenoid -circuit malfunction	Wiring, TCC solenoid, ECM
91	5kip shift warning lamp -circuit malfunction	Wiring, skip shift warning lamp, ECM
93	Transmission fluid pressure (TFP) control solenoid -circuit malfunction	Wiring, poor connection, TFP solenoid
95	Change oil lamp -circuit malfunction	Wiring open circuit/short circuit to groundl short circuit to positive, instrument panel, engine oil life lamp bulb, ECM
96	Engine control module (ECM) -ignition supply voltage low	Wiring open circuit, alternator, ECM
96	Engine oil level warning lamp -circuit malfunction	Wiring open circuit/short circuit to groundl short circuit to positive, instrument panel, engine oil level lamp bulb, oil level sensor, ECM
97	Engine control module (ECM), vehicle speed sensor (VS5) output signal circuit malfunction	Wiring, poor connections, ECM
98	Engine control module (ECM) incorrectly coded	ECM incorrectly coded, ECM
99	Engine control module (ECM) incorrectly coded	ECM incorrectly coded, ECM
99	Engine control module (ECM), tachometer output signal -circuit malfunction	Wiring, poor connections, ECM

Use of the vehicle wiring diagram is recommended to confirm which components are fitted .

o A/C compressor clutch relay0 Exhaust gas recirculation (EGR) solenoid
o A/C condenser blower motor relay0 Malfunction indicator lamp (MIL)
o Engine coolant blower motor rela 0 Torque converter clutch (TCC) solenoid
o Engine coolant ‘hot’ warning lamp0 Transmission shift solenoids (55)
o Evaporative emission (EVAP) canister purge0 Transmission shift warning lamp (MT) valve