Vauxhall Workshop Service and Repair Manuals > Astra H > J Engine and Engine Aggregates | Fuel Injection Systems | Motronic ME 7.6.1/ME 7.6.2/ME 7.6.3/ME 7.6.4/ME 7.9.9 | Diagnostic Information and Procedures | Diagnostic Procedures | Motronic 7.6.1, Z 20 LEH, Z 20 LEL, Z 20 LER | C-xx Fault Isolation Procedures | C-018 O2 Sensor Heater Circuit (Behind Catalyst)

C-018 - O2 Sensor Heater Circuit (Behind Catalyst)

Test

Work Order Description

Nominal Value

T001

Check: Interruption of Voltage Supply Circuit

Ignition OFF
Disconnect wiring harness connector from:
B57 Sensor - Oxygen, Catalytic Converter Check
Remove electrical component from socket:
K2_X125 Relay - Engine Control Unit
Connect fused jumper wire to:
K2_X125 Relay - Engine Control Unit
Socket Terminal 87
&
Battery voltage
Ignition ON
Measure voltage between the following terminals:
B57 Sensor - Oxygen, Catalytic Converter Check
Wiring harness connector (wiring harness side) terminal 1
&
Ground

greater than 11 V

Voltage Measurement

Current Value:

Yes:

No:

T002

Check: Circuit Interruption of Ground Circuit

Ignition OFF
Remove electrical component from socket:
K12_X125 Relay - Radiator Fan
Disconnect wiring harness connector from:
A84 Control Unit - Engine
(Wiring Harness Connector (XC7) )
Measure resistance between the following terminals:
A84 Control Unit - Engine
Wiring harness connector (wiring harness side) terminal 35 (XC7)
&
B57 Sensor - Oxygen, Catalytic Converter Check
Wiring harness connector (wiring harness side) terminal 2

less than 5 Ohm

Resistance Measurement

Current Value:

Ohm

Yes:

No:

Result	Cause Of Fault
E001	Result: Interruption
	Defective component: B57 Sensor - Oxygen, Catalytic Converter Check or A84 Control Unit - Engine Note: The replacement of the components must be done in the listed order. The system must be checked for proper operation after every replacement. Important: Reset the concerned control unit with the diagnostic tester before replacing it. In order to do that, call up the "RESET" function from the PROGRAMMING menu of the current system on the diagnostic tester.

E002	Result: Interruption
	Circuit interruption between: A84 Control Unit - Engine Wiring harness connector (wiring harness side) terminal 35 (XC7) & B57 Sensor - Oxygen, Catalytic Converter Check Wiring harness connector (wiring harness side) terminal 2

E003	Result: Interruption
	Circuit interruption between: X125 Underhood Electronic Module Wiring harness connector (wiring harness side) terminal 29 (XE3) & B57 Sensor - Oxygen, Catalytic Converter Check Wiring harness connector (wiring harness side) terminal 1 or Defective component: X125 Underhood Electronic Module Important: Reset the concerned control unit with the diagnostic tester before replacing it. In order to do that, call up the "RESET" function from the PROGRAMMING menu of the current system on the diagnostic tester.