Troubleshooting, Using VAG 1551

Airbag system troubleshooting, using VAG 1551 fault readouts

Troubleshooting charts

Note

The following charts list all possible airbag system faults, as recognized by the airbag control unit. These faults, stored in the control unit's fault memory, can be displayed on the VAG 1551.

If a component is diagnosed as defective, visually check wiring to that component.

If several components are listed as defective, service one component at a time, erasing the fault memory and re-accessing it, after each fault is corrected.


Fault Readout on VAG 1551 Possible Cause Corrective Action

Deceleration sensor for airbag Defective left sensor. Replace left sensor.
left -G104
defective

Deceleration sensor for airbag Defective right sensor. Replace right sensor.
right -G105
defective

Sensor wire left Wire or connector shorted, Visually check wiring and correct
Short circuit to Positive(1) (or) to positive or ground. as necessary.
Short circuit to Ground(1) Perform Electrical Test, step 1.(2)
If specified value is obtained,
replace airbag control unit (J234).
Sensor wire left Wire disconnected. Visually check wiring and correct
Open as necessary.

Perform Electrical Test, step 1.(2)
If specified value is obtained,
replace airbag control unit (J234).

Sensor wire right Wire or connector shorted, Visually check wiring and correct
Short circuit to Positive(1) (or) to positive or ground. as necessary.
Short circuit to Ground(1) Perform Electrical Test, step 2.(2)
If specified value is obtained,
replace airbag control unit (J234).

(1) Only one of these readouts will be displayed, along with name of component affected. (2) See Electrical Tests, page 18


Fault Readout on VAG 1551 Possible Cause Corrective Action

Sensor wire right Wire disconnected. Visually check wiring and correct
Open as necessary.

Perform Electrical Test, step 2.(2)
If specified value is obtained,
replace airbag control unit (J234).

Deceleration sensor for airbag Connector resistance too Check, and if necessary, correct
left -G104 high. wiring between left deceleration
Open circuit sensor (G104) and airbag control
unit.
or
Replace left deceleration
sensor for airbag.

Deceleration sensor for airbag Connector resistance too Check, and if necessary, correct
right -G105 high. wiring between right deceleration
Open circuit sensor (G105) and airbag control
unit.
or
Replace right deceleration
sensor for airbag.

Sensor wire left Wire damaged, or Visually check wiring and
Value of resistance too large connector defective. connectors, correct as necessary.
or
Perform Electrical Test, step 1.(2)
If specified value is obtained,
replace airbag control unit (J234).

Sensor wire right Wire damaged, or Visually check wiring and
Value of resistance too large connector defective. connectors, correct as necessary.
Perform Electrical Test, step 2.(2)
If specified value is obtained,
replace airbag control unit (J234).

Control unit defective Defective control unit. Replace airbag control unit
(J234).

Airbag Igniter - Driver Side Wire disconnected. Visually check wiring and
-N95 Spiral spring or airbag unit connectors, correct as necessary.
Short circuit to Positive(1) (or) defective. Replace spiral spring.
Short circuit to Ground(1) or
Replace airbag unit.

(1)Only one of these readouts will be displayed, along with name of component affected.
(2)See Electrical Tests, previous page


Fault Readout on VAG 1551 Possible Cause Corrective Action

Airbag Igniter - Driver Side Wire disconnected. Visually check wiring and
-N95 Spiral spring, airbag unit, connectors, correct as necessary.
Open or connector defective.

Replace spiral spring.

or
Replace airbag unit.

Airbag Igniter - Driver Side -N95 Airbag unit, or airbag Replace airbag unit.
control unit defective. or
Value of Resistance too small Replace airbag control unit
(J234).

Airbag Igniter - Driver Side -N95 Damaged wire, connector, Visually check wiring and
spiral spring or airbag unit connectors, correct as necessary.
Value of Resistance too large defective.

Replace airbag unit.

or
Replace airbag control unit (J234).

Airbag control light -K75 Wire, connector or control Visually check wiring and
Short circuit to Positive(1) (or) light defective. connectors, correct as necessry.
Short circuit to Ground(1) Replace airbag control light
Open (K75).

or

Replace airbag control unit (J234).

Firing order correct No faults in system but See CAUTION, page 19
crash data has been stored.

Trigger current indication correct No faults in system but See CAUTION, page 19
crash data has been stored.

Ignition current order correct No faults in system but See CAUTION, page 19
crash data has been stored.

(1)Only one of these readouts will be displayed, along with name of component affected.
(2)See Electrical Tests