Vauxhall Workshop Service and Repair Manuals

Test

Work Order Description

Nominal Value

Check: Transition Resistance of Voltage Supply Circuit

• Ignition OFF
• Disconnect wiring harness connector from:
  A172 Control Unit - Headlamp Levelling (Xenon Light)
• Ignition ON
• Connect test lamp ( 21 W ) and multimeter in parallel and measure voltage between the following terminals:
  A172 Control Unit - Headlamp Levelling (Xenon Light)
  Wiring harness connector (wiring harness side) terminal 23
  &
  Ground

greater than 11 V

Check: Transition Resistance of Voltage Supply Circuit

• Connect test lamp ( 21 W ) and multimeter in parallel and measure voltage between the following terminals:
  A172 Control Unit - Headlamp Levelling (Xenon Light)
  Wiring harness connector (wiring harness side) terminal 23
  &
  A172 Control Unit - Headlamp Levelling (Xenon Light)
  Wiring harness connector (wiring harness side) terminal 24

greater than 11 V

Check: Transition Resistance of Voltage Supply Circuit

• Engine running
• Increase engine speed to 3000 rpm
• Connect test lamp ( 10 W ) and multimeter in parallel and measure voltage between the following terminals:
  A172 Control Unit - Headlamp Levelling (Xenon Light)
  Wiring harness connector (wiring harness side) terminal 23
  &
  Ground

13 ... 14.5 V

Check: Transition Resistance of Voltage Supply Circuit

• Ignition OFF
• Remove electrical component from socket:
  FE33 Fuse
• Ignition ON
• Connect test lamp ( 21 W ) and multimeter in parallel and measure voltage between the following terminals:
  FE33 Fuse
  Input contact
  &
  Ground

greater than 11 V

Check: Transition Resistance of Voltage Supply Circuit

• Ignition OFF
• Remove electrical component from socket:
  K3_X125 Relay - Terminal 15
• Ignition ON
• Connect test lamp ( 21 W ) and multimeter in parallel and measure voltage between the following terminals:
  K3_X125 Relay - Terminal 15
  Socket Terminal 30
  &
  Ground

greater than 11 V

Result

Cause Of Fault

• Defective component:
  A172 Control Unit - Headlamp Levelling (Xenon Light)

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.

• Defective component:
  G8 Alternator

• High transition resistance between:
  A172 Control Unit - Headlamp Levelling (Xenon Light)
  Wiring harness connector (wiring harness side) terminal 24
  &
  Ground

• High transition resistance between:
  X125 Underhood Electronic Module
  Socket Terminal 39 (XE2)
  &
  A172 Control Unit - Headlamp Levelling (Xenon Light)
  Wiring harness connector (wiring harness side) terminal 23

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.

• Defective component:
  K3_X125 Relay - Terminal 15
  or
  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.

Note:

The replacement of the components must be done in the listed order.

The system must be checked for proper operation after every replacement.

• 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.