Fuel Temperature Sensor, checking

NOTE: Use only gold-plated terminals when servicing terminals in harness connector.

Recommended special tools and equipment

V.A.G 1526 multimeter or V.A.G 1715 multimeter
V.A.G 1594 connector test kit
Wiring diagram

Requirement

Fig 1: Identifying Main Fuse Panel

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The respective fuses of Diesel-Direct fuel injection system must be OK:

Refer to Electrical Wiring Diagrams, Troubleshooting & Component Locations

Battery voltage must be at least 11.5 volts.
For vehicles with automatic transmission, selector lever must be in -P-.
Parking brake must be engaged.
Ignition is switched off.

Test sequence

Fig 2: Location Of Fuel Temperature Sensor G81

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Disconnect 2-pin connector (arrow) from Fuel Temperature Sensor -G81-.
Measure resistance between sensor terminals.

Fig 3: Temperature & Resistance Values Graph

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See diagram for specified value

Range A displays resistance values for the temperature range of 0 to 65 ° C, range B displays resistance values for the temperature range of 65 to 100 ° C.

Read-out examples:

30 ° C corresponds to a resistance of 3790 to 4270 Ω
80 ° C corresponds to a resistance of 600 to 660 Ω

If specified value is not obtained:

Replace Fuel Temperature Sensor -G81-.
Erase DTC memory of Engine Control Module (ECM). Refer to Diagnostic mode 4: Reset/erase diagnostic data
Generate readiness code. Refer to Readiness code, generating

If specified value is obtained:

Check wires to Engine Control Module (ECM) according to wiring diagram. Refer to Fuel Temperature Sensor, checking .

Check wires to control module

Connect test box (1598/42) to Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248- wiring harness using adapter cable (V.A.G 1598/39-1). Refer to Test box, connecting for wiring test

Fig 4: 2-Pin Harness Connector & Terminals

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Check wires between test box and connector for open circuit according to wiring diagram.

Terminal 1 + socket 40

Terminal 2 + socket 39

Wire resistance: max. 1.5 Ω

Check wires for short circuit to each other, to vehicle Ground (GND) and to B+.

Specified value: ∞ Ω

If no malfunctions are found in wires:

Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248-. Refer to Engine Control Module (ECM), replacing .