Diagnosi centralina

Codici di errore di diagnosi della centralina


Per eseguire l'autodiagnosi della centralina elettronica è necessario inserire la chiave ed accendere/spegnere il quadro per due volte, alla terza accensione del quadro apparirà un numero al quale corrisponde una anomalia rilevata dal sistema di check del veicolo.

1984 1986

12 Terminals 6 and 7 connected. If appears when terminals not connected and engine running, no signal between distributor and computer.
13 Oxygen sensor circuit. Check TPS adjustment. Check O2 wiring and sensor.
14 Coolant sensor circuit. Overheating or fault in wiring or coolant sensor.
15 Coolant sensor circuit. Low temperature or fault in wiring or coolant sensor.
21 TPS circuit. Signal voltage high. Check TPS and adjustment. Also wiring at both computer and TPS ends.
23 Mixture control (M/C). Check wiring at M/C solenoid and computer. Clear code and re-check after driving.
34 MAP sensor. Check wiring and hose in case of leak. Otherwise replace.
41 No distributor signal. Check distributor wiring and pick-up coil connections.
42 EST or bypass problem. Check wire to terminal 12 on ECM or faulty HEI module can cause same code.
44 Lean exhaust. Check for sticking M/C solenoid also terminals 9 and 14 at ECM. Vacuum leakage or faulty O2 sensor.
44-45 O2 sensor or circuit. O2 circuit wiring or sensor faulty.
45 Rich exhaust. Check for sticking M/C solenoid and wiring plus charcoal canister for fuel. O2 sensor faulty.
51 PROM fault. Needs specialist or dealer diagnostics.
54 M/C solenoid Check wiring at M/C and ECM. Faulty M/C.
55 Reference voltage. Check short to ground on ECM terminal 21 wire. O2 sensor or ECM faulty.


1991 - 1997
11 No crank signal to computer. Fault in wiring between crankshaft position sensor (CPS) and ECM ( PCM or computer ) or faulty� CPS.
12 Battery disconnected. Battery or power to the ECM disconnected in the last 50 key cycles.
13 MAP Sensor. No change in Manifold Absolute Pressure (MAP) between engine off and on. Check circuit and MAP sensor.
14 MAP Sensor. MAP sensor voltage too high or low. Check circuit and sensor.
15 Speed sensor or circuit. No signal detected from speed sensor. Check circuit and sensor.
17 Engine running too cold. Wrong or faulty thermostat. Check also sensor and circuit for fault.
21 Oxygen sensor or circuit. O2 sensor or wiring faulty.
22 Coolant sensor or circuit. Check temp sensor and wiring.
23 Intake air temp or circuit. Check air temp sensor and wiring.
24 Throttle Position Sensor (TPS) Check TPS sensor and wiring.
25 Idle Air Control circuit (IAC) Check IAC sensor and wiring.
26 Injector circuit resistance. Peak injector current has not been reached or injector circuits have resistance
27 Fuel injector control circuit. Will need specialist diagnostics.
31 Evaporative control circuit. Fault in fuel evaporative control circuit or hoses.
33 Air conditioning clutch relay. Wiring to A/C clutch fault.
34 Cruise control circuit. Fault in circuit.
35 Cooling fan relay. Check relay and circuit.
36 Air switch solenoid circuit. Air switch solenoid circuit (non-turbo) or the waste gate solenoid on turbocharged models
37 Torque converter clutch. Needs specialist or dealer diagnostics.
41 Alternator field switch. Switch not operating correctly and check charging system.
42 Automatic shutdown relay. Check relay and circuit. Needs specialist or dealer diagnostics.
43 Misfire. Misfire in one or more cylinders.
44 Battery temperature sensor. Needs specialist or dealer diagnostics.
46 Battery over voltage. Check charging system.
47 Battery under voltage. Check charging system.
51 O2 detects lean mixture. Check sensor and circuit and for vacuum leaks.
52 O2 detects rich mixture. Check fuel injection system and sensor.
53 Powertrain Control Module. PCM (ECM) fault. Needs specialist or dealer diagnostics.
54 Distributor sync pickup. Change sync sensor in distributor.
55 End of code. Trouble codes finished or none recorded.
61 BARO solenoid BARO solenoid failure
62 Emissions reminder. Emissions maintenance reminder. Needs specialist or dealer diagnostics.
63 Controller failure. EEPROM write denied. Needs specialist or dealer diagnostics.
64 Flexible fuel sensor. Flexible fuel (methanol) sensor indicates concentration sensor input more/less than acceptable voltage
65 Manifold tune value. Manifold tune valve solenoid circuit open or shorted
66 TCM to PCM failure. No message from the Transmission Control Module (TCM) to the Powertrain Control Module (PCM)
72 Catalytic converter circuit. Needs specialist or dealer diagnostics.
76 Fuel pump bypass relay circuit. Needs specialist or dealer diagnostics.
77 Cruise control system. Check power to cruise control solenoids.


1998 - 2002

11 No camshaft reference during cranking signal detected during engine cranking.
12 Battery power to PCM was disconnected.
13 No variation in MAP from start to run sensor is detected. No difference recognized between engine MAP reading and barometric pressure reading at start- up.
14 MAP sensor input below or above acceptable voltage.
15 No vehicle speed signal. No vehicle distance (speed) sensor signal detected during road load conditions or shaft speed less than 60 rpm when speed above 15 mph.
17 Engine is cold too long. Engine coolant temperature remains below normal operating temperatures during vehicle travel (thermostat).
21 O2 sensor voltage not detected from the oxygen sensor input. Or 02 sensor input voltage maintained above or below normal operating range.
22 Coolant sensor voltage. Sensor input above or below acceptable voltage.
23 Charge air temp. sensor. Sensor input above or below acceptable voltage.
24 TPS voltage sensor input above or below the minimum acceptable voltage. Or TPS signal does not correlate to MAP sensor.
25 AIS motor circuits. An open or shorted condition detected in one or more of the IAC control circuits. Or target idle speed not met.
26 Peak injector current has not been reached or injector circuits have resistance
27 Injector # X control circuit Injector output driver does not respond properly to the control signal.
31 An open or shorted condition in Purge Solenoid circuit. Incorrect vapour flow detected. Possible leak or blocked between solenoid and fuel tank.
33 A/C clutch relay circuit An open or shorted condition detected in the A/C clutch relay circuit.
34 S/C solenoid circuits An open or shorted condition detected in the speed control vacuum or vent solenoid circuits. Voltage too high or low.
35 Radiator Fan Relay in open or shorted condition detected in the radiator fan relay circuit. ( 2.5L only ).
36 Air switch solenoid circuit (non-turbo) or the wastegate solenoid on turbocharged models
37 No speed difference detected at 3 to 4 shift or no lockup in torque converter. Problem with trans solenoid with wrong pressure or voltage. Speed to trans ratio below minium required. Park/Neutral switch stuck.
41 Alternator field circuit in open or shorted condition detected in the alternator field control circuit.
42 ASD ( auto shut down ) or fuel pump relay control circuit in open or shorted condition detected. Or no voltage sensed at controllers. No fuel sensor signal detected or changed over time at PCM.
43 Cylinder misfire detected.
44 Battery temperature voltage out of range ( too high or low ).
45 Trans temperature/ Governor pressure voltage out of range. Less than 1.55 or above 3.73volts for temperature and less than .1 or above 4.89 volts. Trans temp. to high or low. OD switch input too low for more than 5 mins.
46 Charging system voltage high. Battery voltage sense input above target charging voltage during engine operation.
47 Charging system voltage low. Battery voltage sense input below target charging voltage during engine operation.
51 O2 signal below centre. Oxygen sensor signal indicates lean fuel/air ratio condition during engine operation.
52 O2 signal above centre. Oxygen sensor signal indicates rich fuel/air ratio condition during engine operation or Adaptive memory at lean limit.
53 Internal Controller failure in PCM. Internal Controller fault condition detected.
54 No Sync signal. No camshaft position signal detected during engine cranking.
61 BARO solenoid failure
62 Controller failure. EMR miles not stored.
63 Failure to write to EEPROM location by PCM.
64 Flexible fuel (methanol) sensor indicates concentration sensor input more/less than acceptable voltage.
65 Manifold tune valve solenoid circuit open or shorted
66 No message from the Transmission Control Module (TCM) to the Powertrain Control Module (PCM)
72 Catalyst efficiency below required level.
76 Fuel pump resistor Open or shorted condition by-pass relay circuit detected in fuel pump by-pass relay circuit
77 Malfunction detected with power feed to speed control servo solenoids


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