Engine ECU fault codes  2.0 8v, 16v, Ecotech, Turbo, V6

Information from Bob Rawle.

Dis-engage the diagnostics plug from its socket.

This is positioned at the rear of the engine bay on the passengers side on cavalier/calibra’s, on the astra3 it’s in the fusebox, and on vectra’s around the handbrake and omega on the panel by the fusebox.

 It has 10 pins.

Short pins A & B to read the engine ecu codes. Brown & Brown/yellow 16 pin connectors, On the Vectra / Omega short pins 4 & 6

Start the engine, management warning light will start to flash as follows.

The code 12 is first flashed three times, this is a marker.

If a code is stored it is then flashed three times.

The code 12 is then flashed three times, this is a separator.

If a 2nd code is stored it is then flashed three times or the first code is repeated.

The code 12 is then flashed three times, this is a separator.

etc

Once all codes have been displayed then stop engine and remove wire.

To clear codes you should disconnect the battery for a minimum of

10 minutes and then re-connect. This also has the effect of resetting

the ECU parameters to their defaults and forces the adaptive learning

circuits to start again. Within approx. 200 miles the ECU will have adapted.

12 Diagnosis Initiation / separator

13 Oxygen sensor - open circuit

14 Coolant temperature sensor - voltage low

15 Coolant temperature sensor - voltage high  

16 Knock signal circuit    - no voltage change

17 Knock signal circuit 2  - no voltage change

18 Knock control module (ECU)

19 Incorrect RPM signal (Crankshaft sensor - incorrect signal)

21 Throttle position sensor - voltage high

22 Throttle position sensor - voltage low

23 Knock sensor - out of range

24 Speed Sensor (MPH)

25 Injector 1 - voltage high

26 Injector 2 - voltage high

27 Injector 3 - voltage high

28 Injector 4 - voltage high

29 Injector valve 5 - voltage high    (Fuel pump relay voltage low)

31 No engine RPM signal  Engine not running (Crankshaft Sensor - No Signal)

32 Fuel pump relay - voltage high

33 Map Sensor (Voltage High)

34 Map Sensor (Voltage Low)

35 Idle Control Valve Stepper Motor (No Idle Speed Control)

38 Oxygen circuit - voltage low (weak)

39 Oxygen circuit - voltage high (rich)

41 1 gear ident switch - voltage low  C20LET  OR  EST Line Coil Cylinder 2 & 3 (Voltage High) M2.8 / XEV

42 1 gear ident switch - voltage high C20LET  OR  EST Line Coil Cylinder 1 & 4 (Voltage High) M2.8 / XEV

43 Linear EGR System XEV

44 Oxygen circuit - voltage low (weak)

45 Oxygen circuit - voltage high (rich)

47 Linear EGR Position XEV

48 Battery voltage - low

49 Battery voltage - high

51 ECU faulty  (memory failure)

52 Check engine  light - voltage high

53 Fuel pump relay - voltage low

54 Fuel pump relay - voltage high

55 ECU faulty (Hardware fault)

56 Idle air control - voltage low  (or high !?!)

57 Idle air control - voltage high (or low  !?!)

61 Fuel tank vent valve - voltage low

62 Fuel tank vent valve - voltage high

63 EST Line Coil Cylinder 2 & 3 (Voltage Low)    M2.8/XEV

64 EST Line Coil Cylinder 1 & 4 (Voltage Low)    M2.8/XEV

65 Idle CO potentiometer - voltage low

66 Idle CO potentiometer - voltage high

67 Idle position switch - voltage low    (idle position switch not opening)

69 Intake air temperature - voltage low

71 Intake air temperature - voltage high

72 Full position switch - voltage high   (full load not opening)

73 Air flow sensor - voltage low

74 Air flow sensor - voltage high

75 Torque control - voltage low     (Transmission Switch)

76 Torque control - continuous      (Transmission Switch)

79 Full load inhibitor - voltage low  (Traction Control Signal)

81 Injector valve 1 - voltage low

82 Injector valve 2 - voltage low

83 Injector valve 3 - voltage low

84 Injector valve 4 - voltage low

85 Injector valve 5 - voltage low

86 Injector valve 6 - voltage low   V6

87 A/C cut-off relay - voltage low

88 A/C cut-off relay -  voltage high

92 Cam shaft sensor failure XEV

93 Hall sensor - voltage low   (Quad Driver Module)

94 Hall sensor - voltage high

95 Hot start valve  - voltage low

96 Hot start valve  - voltage high

97 Ignition/Injection cut off - voltage high  (Traction Control Signal)

113 Boost control out of range

114 Boost pressure Idle above upper limit

115 Boost pressure Full below lower limit

116 Boost pressure Full below upper limit

117 Wastegate valve  - voltage low

118 Wastegate valve  - voltage high