Exhaust Gas Temperature Sensor 1, Checking
Exhaust Gas Temperature Sensor 1, Checking
Special Tools and Equipment
- V.A.G 1526A
- V.A.G 1527B
- V.A.G 1594A
- V.A.G 1598/31
- VAS 5051 with VAS 5051/1
NOTE:
- VAS 5051 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 measuring value block " in selection -1 -.
Display on VAS 5051 :
- 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
NOTE: Fuse for exhaust temperature sensor OK. See Electrical Wiring Diagrams, Troubleshooting Component Locations
- 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 -
CAUTION: 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.