With Manufacturer's Scan Tool

Engine Speed (RPM) sensor, checking

The Engine Speed (RPM) sensor -G28- is a speed and reference mark sensor. The engine will not start if there is no speed signal. If the speed signal fails when the engine is running, it will cause the engine to stall immediately.

Special tools and equipment
- VAG1551 or VAG1552 Scan Tool (ST) with VAG1551/3 adapter cable
- VAG1598/22 test box
- Multimeter US1119 (Fluke 83 or equivalent)
- VW1594 connector test kit
- Wiring diagram

Checking conditions
- Battery voltage: min. 11.5 volts

Checking




- Disconnect gray 3-pin harness connector from Engine Speed (RPM) sensor (arrow).
- Measure sensor resistance between terminals 2 and 3 of connector -1-.
- Specified value: 480-1000 Ohms
- Check sensor for short circuit between terminals 1 and 2 and terminals 1 and 3.
- Specified value: Infinity Ohms

If the specifications are not obtained:
- Replace Engine Speed (RPM) sensor -G28-.

If no sensor malfunction is detected:



- Connect VAG1598/22 test box to ECM harness connector.
- Check wiring for open circuit between ECM/test box and 3-pin harness connector.
- Connector terminal 1 to ECM/test box socket 67
- Connector terminal 2 to ECM/test box socket 63
- Connector terminal 3 to ECM/test box socket 56
- Specified value: max. 1.5 Ohms
- Check wiring for short circuit between ECM/test box and 3-pin harness connector, according to wiring diagram.

If wiring is OK:
- Remove sensor and check sensor wheel for secure fit, damage and run-out.
- Check that spacer for sensor is seated securely.

NOTE: There is one large gap on the sensor wheel. This gap is the reference mark and does not mean that the sensor wheel is damaged.

- Check readiness code. If Diagnostic Trouble Code (DTC) memory has been erased, or ECM was disconnected, generate new readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If sensor wheel is OK:
- Replace Motronic ECM -J220-. Service and Repair