Exhaust Gas Temperature (EGT) Sensor 1 -G235-, Checking

Exhaust Gas Temperature (EGT) Sensor 1 -G235-, Checking







Special Tools and Equipment
- V.A.G 1526A
- V.A.G 1527B
- V.A.G 1594A
- V.A.G 1598/31
- VAS5051 with VAS5051/1

Test requirements:
- VAS5051 tester connected and vehicle On Board Diagnostic (OBD) -01 Engine electronics- selected.
- Read DTC memory

Test sequence
- Read measuring value block display group 112, engine at idle.
- Select diagnostic function "08 - read measured value block" in selection -1-.
- Check indication in display field -1-.
- Increase engine RPMs.
- Exhaust temperature must rise

If exhaust temperature remains constant or indicates an implausible value:
- Check voltage supply.
- Check wire connections.

Checking voltage supply

Test requirement:
- Fuse for exhaust temperature sensor OK.

- Switch ignition off.
- Remove cover in front of intake manifold.







- Disconnect electric harness connector -arrow- at Exhaust Gas Temperature (EGT) Sensor 1 -G235-.







- Connect V.A.G 1527B voltage tester as follows:

Harness connector Terminal Measure to
3 Engine Ground (GND)

- Operate starter briefly.
- LED must light up.

If LED does not light up:
- Perform the following tests marked with dots:
- Check wire connection from Exhaust Gas Temperature (EGT) Sensor 1 -G235- to Fuel Pump (FP) relay via fuse for open circuit.

- Check Fuel Pump (FP) relay.

Checking wire connections







- Connect V.A.G 1598/31 test box to harness connectors of wiring harness (do not connect ECM). Clamp test box Ground (GND) clip to Ground (GND) (arrow):

WARNING: To avoid damaging electronic components, set measuring range before connecting test leads and observe all test requirements.







- Check the following wire connection for open circuit and short circuit to Ground (GND) and B-:

Harness connector Terminal V.A.G 1598/31 test box Socket
1 61
2 50

- Repair open circuit in wiring or short circuit if necessary.

If no malfunctions are detected:
- Replace exhaust gas temperature sensor.