Vauxhall Workshop Service and Repair Manuals

Test

Work Order Description

Nominal Value

Check: Interruption of Voltage Supply Circuit

• Ignition OFF
• Disconnect wiring harness connector from:
  B26 Sensor - Atmospheric Pressure
• Ignition ON
• Measure voltage between the following terminals:
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 1
  &
  Ground

4.8 ... 5.2 V

Check: Short to Voltage/Interruption of Ground Circuit

• Measure voltage between the following terminals:
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 1
  &
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 2

4.8 ... 5.2 V

Check: Short to Voltage of Signal 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 )
• Ignition ON
• Measure voltage between the following terminals:
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 3
  &
  Ground

less than 0.3 V

Check: Short to Ground of Signal Circuit

• Ignition OFF
• Measure resistance between the following terminals:
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 3
  &
  Ground

greater than 500 kOhm

Check: Interruption of Signal Circuit

• Measure resistance between the following terminals:
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 3
  &
  A84 Control Unit - Engine
  Wiring harness connector (wiring harness side) terminal 60 (XC7)

less than 5 Ohm

Check: Mechanical Functionality

• Check mechanical functionality of the following components and all attached parts:
  B26 Sensor - Atmospheric Pressure
• Check electro-pneumatic pressure converter, bypass valve adjuster, bypass valve and corresponding pneumatic lines for correct functioning
• Check turbocharger
• Check intake system/charge air hoses for leaks (secondary air, porosity and blockages)

Mechanical function check okay?

Check: Short to Voltage/Interruption of Ground Circuit

• Measure voltage between the following terminals:
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 1
  &
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 2

greater than 5.2 V

Check: Interruption of Voltage Supply Circuit

• Ignition OFF
• Disconnect wiring harness connector from:
  B26 Sensor - Atmospheric Pressure
• Ignition ON
• Measure voltage between the following terminals:
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 1
  &
  Ground

greater than 5.2 V

Result

Cause Of Fault

• Defective component:
  B26 Sensor - Atmospheric Pressure
  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.

• Repair or replace defective component

• Circuit interruption between:
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 3
  &
  A84 Control Unit - Engine
  Wiring harness connector (wiring harness side) terminal 60 (XC7)

• Short circuit to ground between:
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 3
  &
  A84 Control Unit - Engine
  Wiring harness connector (wiring harness side) terminal 60 (XC7)

• Short circuit to voltage between:
  A84 Control Unit - Engine
  Wiring harness connector (wiring harness side) terminal 60 (XC7)
  &
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 3

• Short circuit to voltage between:
  A84 Control Unit - Engine
  Wiring harness connector (wiring harness side) terminal 10 (XC7)
  &
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 2

or

• Defective component:
  A84 Control Unit - Engine

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.

• Circuit interruption between:
  A84 Control Unit - Engine
  Wiring harness connector (wiring harness side) terminal 10 (XC7)
  &
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 2

or

• Defective component:
  A84 Control Unit - Engine

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.

• Short circuit to voltage between:
  B26 Sensor - Atmospheric Pressure
  Wiring harness connector (wiring harness side) terminal 1
  &
  A84 Control Unit - Engine
  Wiring harness connector (wiring harness side) terminal 7 (XC7)