Checking interference to the engine speed (RPM) sensor

Check the engine speed (RPM) sensor connector. Check for contact resistance and oxidation.

The engine speed (RPM) sensor is sensitive to interference from surrounding power cables, the starter motor cable for example, or similar high amperage cables. This occurs when starting the engine for example.

Interference can cause difficulty in starting the engine, the engine does not start at all, the tachometer flickers at start attempts etc.

Causes of interference can be:

• surrounding power cables, for example an incorrectly routed starter motor cable
• incorrectly routed transmission bolted joints for the engine.

Checking the power cable 

Check for incorrectly routed power cables (routed too close to the engine speed (RPM) sensor).

Checking the bolted joints 

When removing and installing the transmission it is important that all the bolts for the engine are correctly tightened. Incorrectly tightened bolts can cause poor ground connection and interfere with the engine speed (RPM) sensor. Check that all the bolts from the transmission to the engine are correctly tightened.

Other information: 

• See Contents
• To access or replace the engine speed (RPM) sensor, see Replacing the engine speed (RPM) sensor .

Remedy as necessary

• Continue 

  Refer to Verification