Engine speed (RPM) sensor -G28-, checking
WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
Special tools and equipment
- VAG1526 A
- VAG1594 A
- VAG1598/31
NOTE:
The engine speed sensor is a combined speed sensor and reference mark sensor. The engine cannot be started without a signal from the Engine speed (RPM) sensor -G28-. If the signal from the Engine speed (RPM) sensor -G28- fails while the engine is running, the engine will cut out immediately.
Test sequence
- Before performing test, make sure that sensor is correctly installed and firmly seated.
- Disconnect connector to engine speed sensor. See Figure.
- Connect multimeter between terminals 2 and 3 to measure resistance.
- Specified value: 730 to 1000 Ω
NOTE:
The resistance value of the engine speed sensor is associated with a temperature of 20°C. The resistance increases if the temperature increases.
If specified value is not attained:
- Install a new engine speed sensor.
If specified value is attained:
- Connect multimeter between terminals 2 and 1 (screen) and 3 and 1 (screen) to measure resistance.
- Specified value: each case ∞ Ω (no continuity)
If specified value is not attained:
- Install a new engine speed sensor.
If specified value is attained:
- Connect test box VAG1598/31 to wiring harness for engine control module; do not connect engine control module. Refer to Wiring and component check with test box VAG 1598/31 .
- Check for open circuit and short to positive or ground in following wiring connections:
| Connector Terminal |
Test box VAG1598/31 Socket |
| 1 (screening) | 108 |
| 2 (ground) | 90 |
| 3 (signal) | 82 |
- Repair any open/short circuit as necessary.
If no wiring malfunction is detected:
- Replace engine control module. Refer to Engine Control Module (ECM) (without metal anti-theft housing), replacing .