Test sequence
Component location. See item 6 in COMPONENT LOCATIONS, OVERVIEW .
NOTE:
The engine speed (RPM) 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.
- Before performing test, make sure that sensor is correctly installed and firmly seated.
- Disconnect engine speed (RPM) sensor connector -G28- -Pos. 3-.
NOTE:
To gain access to the connector, remove coolant expansion tank bolt -arrow- and move expansion tank to the side. Fuel hoses remain connected.
- Connect multimeter between terminals 2 and 3 to measure resistance.
- Specified value: 730...1000Ω
NOTE:
The resistance value of the engine speed (RPM) sensor -G28- is associated with a temperature of 20 °C. The resistance increases if the temperature increases.
If specified value is not obtained:
- Install new engine speed (RPM) -G28-.
- Connect multimeter between terminals 2 and 1 -screen- and 3 and 1 -screen- to measure resistance.
- Specified value: each case INFINITY Ω (no continuity)
- Install a new Engine speed (RPM) sensor -G28-.
- Connect test box V.A.G 1598/31 to wiring harness for ECM; do not connect ECM. See ELECTRICAL TESTING USING VAG1598/31 TEST BOX .
- Check for open circuit, short to positive, or short to ground in following wiring connections:
If specified value is obtained:
If specified value is not obtained:
If specified value is obtained:
ENGINE SPEED SENSOR: TERMINAL 1, 2, 3 & SOCKET 108, 90, 82
| Connector terminal | Test box V.A.G 1598/31 Socket |
|---|---|
| 1 (screening) | 108 |
| 2 (ground) | 90 |
| 3 (signal) | 82 |
- Repair any open/short circuit as necessary.
If no wiring problems are found:
- Replace ECM. See ENGINE CONTROL MODULE (ECM) (WITHOUT METAL ANTI-THEFT HOUSING), REPLACING .