With Manufacturer's Scan Tool
Fuel Temperature Sensor -G81-, Checking
Special tools
- VAG 1551/1552 Scan Tool using VAG 1551/3 Adapter cable
- VAG 1598/22 Test Box (MY 1999)
- VAG 1598/31 Test Box (from MY 2000)
- Fluke 83 multimeter
- VW 1594 Adapter kit
- Wiring diagram
Test sequence
- Connect VAG 1551/1552 Scan Tool.
- Start engine and let idle.
- Press 0 and 1 buttons to select Address word 01: "Engine electronics"
Display will appear as shown (example only)
038906018M 1.9l R4 EDC 00AG 1813 ->
Coding 0001 WSC XXXXX
- Press -> button.
Display will appear as shown
Rapid data transfer HELP
Select function XX
- Press 0 and 8 buttons to select Function 08: "Read measuring value block".
- Press Q button to enter input.
Display will appear as shown
Read measuring value block HELP
Input Display group number XXX
- Press buttons 0, 0 and 7 to select "Display group 7".
- Press Q button to enter input.
Read measuring value block 7
15.4 °C 15.9 °C 16.7 °C
Display will appear as shown
If an unrealistic value appears in Display zone 1 or a substitute temperature of -5.4 °C is displayed
- Check Fuel Temperature Sensor -G81-and wiring to sensor as follows:
- Press -> button.
Display will appear as shown
Read measuring value block HELP
Input Display group number XXX
- Press 0 and 6 buttons to select Function 06: "End output".
- Switch OFF ignition.
- Disconnect 10-pin -G81- harness connector (connection to Diesel injection pump metering control).
- Measure Fuel Temperature sensor resistance between terminals 4 + 7.
Specification chart
Scale A shows resistance values for temperature range 0 to 50 °C and scale B the values for temperature range 50 to 100 °C.
Examples:
- 30 °C corresponds to a resistance between 1500 and 2000 Ohms
- 80 °C corresponds to a resistance between 275 and 375 Ohms
If specification not obtained
- Replace Diesel injection pump.
- Display the Readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If DTC memory was erased
- Set the Readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If specification obtained
- Connect VAG 1598/22 (or 1598/31) Test Box to ECM wiring harness.
- Check wiring for open circuit between Test Box and harness connector using Wiring diagram.
Up to MY 1999
- Terminal 7 + socket 53
- Terminal 4 + socket 76
From MY 2000
- Terminal 7 + socket 111
- Terminal 4 + socket 103
Wire resistance: 1.5 Ohms maximum
- Check wires for short to one another, to Ground and to Battery +
Specification: Infinity Ohms
If wiring OK
- Replace Engine Control Module - J248-
- Display the Readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If DTC memory was erased
- Set the Readiness code. Monitors, Trips, Drive Cycles and Readiness Codes