Fuel Temperature Sensor: Testing and Inspection
Diagnostic Procedures
Fuel Temperature Sensor, Checking
• Cylinder bank 1 is located in direction of travel, right.
• Cylinder bank 2 is located in direction of travel, left.
• Use only gold-plated terminals when servicing terminals in harness connector.
Special tools, testers and auxiliary items required
• Multimeter (VAG1526) or Multimeter (VAG1715)
• Connector test kit (VAG1594)
• Wiring diagram
Test Prerequisites
• Fuses in E-box (plenum chamber, left) must be OK:
• Battery voltage must be at least 11.5 volts.
• Ignition is switched off.
Fuel Temperature Sensor 1, Test Sequence
- Disconnect 2-pin connector from Fuel Temperature Sensor (G81) --> [ (Item 8) * ].
- Measure resistance between terminals on sensor.
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 ohms
• 80 °C corresponds to a resistance of 600 to 660ohms
If specified value is not obtained:
- Replace Fuel Temperature Sensor (G81) --> [ (Item 8) * ].
- Erase DTC memory of Engine Control Module (ECM) --> [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09
- Generate readiness code --> [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.
If specified value is obtained, check Control Module Wires
Control Module Wires, Checking
- Connect test box ((VAG1598/42)) to Engine Control Module (ECM) (J623) wiring harness using adapter cable ((VAG1598/39-1)) , connecting test box for wiring test.
- 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. 1.5ohms
- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+.
Specified value: infinite ohms
If no malfunctions are found in wires:
- Replace Engine Control Module (ECM) (J623) --> [ Engine Control Modules, Replacing ] Engine Control Modules, Replacing.
Fuel Temperature Sensor 2, Test Sequence
- Disconnect 2-pin connector from Fuel Temperature Sensor 2 (G248) --> [ (Item 11) * ].
- Measure resistance between terminals on sensor.
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 ohms
• 80 °C corresponds to a resistance of 600 to 660ohms
If specified value is not obtained:
- Replace Fuel Temperature Sensor 2 (G248) --> [ (Item 11) * ].
- Erase DTC memory of Engine Control Module (ECM) --> [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.
- Generate readiness code --> [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.
If specified value is obtained, check Control Module Wires
Control Module Wires, Checking
- Connect test box ((VAG1598/42)) to Engine Control Module 2 (J624) wiring harness using adapter cable ((VAG1598/39-1)) , connecting test box for wiring test.
- 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. 1.5ohms
- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+.
Specified value: infinite ohms
If no malfunctions are found in wires:
- Replace Engine Control Module 2 (J624).