Cam & Crank Sensors
Crank SensorIf the sensor fails the engine will not start. The sensor output can be observed with a scope, or if a voltmeter is used a reading of about 7V can be seen during idle.
^ On 95MY Range Rover, check the mounting plug security. Vehicles past SA316306 have this mounting plug welded into position. On vehicles prior to that VIN the sensor tip may become inserted too deep into the reluctor teeth. DO NOT attempt to shim the sensor away from its mounting to alleviate this. Contact the HelpLine for further guidance on this issue.
^ GEMS box clamp may trap wire shorting signal to shield wire.
^ Crank sensor retention on 96MY Discovery is achieved with a single bolt. Check crank sensor security if a problem is apparent.
Camshaft Sensor
The camshaft sensor works off 12V and can easily be checked by measuring the signal to the GEMS ECM to see if it switches between 12V and 0V as the engine is slowly turned over by hand. If the engine is turned over too quickly (by cranking) you will see a average value on the voltmeter of about 7V. If an output is measured, chances are that the sensor is working properly.
Failure of the sensor will not stop the engine from running. It is possible for a cam sensor fault to be flagged by the following two causes.
^ Minor Crank sensor reluctor ring damage can cause a camshaft sensor fault(s). It is vital therefore that the reluctor ring is carefully checked.
^ The camshaft timing gear must be correctly aligned and secured. otherwise, the signals from the cam/crank sensors will be out of synchronization and can lead to faults being flagged or the engine running roughly. If the camshaft timing gear comes into contact with the cam sensor, it would be possible for the sensor to fail.