Contents: On vehicles with a 7-pin fuel pump…↓ On vehicles with a 10-pin fuel pump…↓ On all cars ↓ On vehicles with a 7-pin fuel pump…↓ On vehicles with a 10-pin fuel pump…↓ On all cars ↓
1. Connect the VAG 1551 tester and, by entering "01" "Engine electronics", select the engine control unit. The engine should be idling. The display should show the following information:
- Fast data exchange HELP
- Dial function XX
2. Press "08" to select the "Read Block of Measured Values" function and confirm with the "Q" button. The display should show the following information:
- Reading the measured value block HELP
- Enter group number XX
3. Press "007" to select the "Display Group 007" function and press "Q". The display should show the following information:
- Reading measured value block 7 →
- 15.4°C 15.9°C 16.7°C
4. If field 1 does not display actual information or is replaced by a temperature of -5.4°C, check the sensor and the wires going to it. Click "→".
5. Press "06" to select the "Quick Data Exchange" function and confirm by pressing the "Q" button.
6. Turn off the ignition.
7. Disconnect the wiring connector from the sensor (fuel injection quantity control mechanism connector).
On vehicles with a 7-pin fuel pump connector
8. Measure the resistance between pins 4 and 7 of connector 1 (figure 3.61).
Figure 3.61. On vehicles with a 7-pin fuel pump connector: measure the resistance between pins 4 and 7 of connector 1.
On vehicles with a 10-pin fuel pump connector
9. Measure the resistance between pins 4 and 7 of connector 1 (figure 3.62).
Figure 3.62. On vehicles with a 10-pin fuel pump connector: measure the resistance between pins 4 and 7 of connector 1.
On all cars
10. The set resistance value is shown in the figure 3.55. Area A shows the resistance in the temperature range of 0-50°C, area B shows the resistance in the temperature range of 50-100°C. For example, a temperature of 30°C corresponds to a resistance of 1500-2000 ohms; a temperature of 80°C corresponds to a resistance of 275-375 Ohms.
11. If the specified value is not achieved, replace the fuel pump.
12. If the specified value is reached, connect the tester to the wiring connector.
On vehicles with a 7-pin fuel pump connector
13. Check the wires between the tester and socket 1 for continuity: pin 7 + socket 63, pin 4 + socket 33 (figure 3.63). Specified value: max 1.5 ohm.
Figure 3.63. Check the wires between the tester and connector 1 for an open circuit.
14. Check the connector wires for short circuit.
Set value: ∞ Ohm.
On vehicles with a 10-pin fuel pump connector
15. Check the wires between the tester and connector 1 for an open circuit. On vehicles with a 68-pin control unit connector: pin 7 + socket 63, pin 4 + socket 33. Specified value: max. 1.5 ohms. On vehicles with a 121-pin control unit connector: pin 7 + socket 111, pin 4 + socket 103. Specified value: max. 1.5 ohms.
16. Check the connector wires for short circuit.
Set value: ∞ Ohm
On all cars
17. If there are no faults in the wires, replace the fuel injection system control unit.
Figure 3.64. Check the wires between the tester and connector 1 for an open circuit.
Visitor comments