Rover Group Cars
Lucas AB17 ECU Ignitiont Sensor Information
Crankshaft Angle Sensor (CAS)
(Note CAS fitted to later the Rover MEMS system is generally similar)
Location: On rear of engine, it is mounted on the engine side of adapter plate between engine and bellhousing.
Description: Inductive pick up, connecting plug often blue in colour.
Connection to ECU: Connects to ignition ECU via pins 4 and 6.
Output Voltage: Sine wave, about 5 volts peak to peak (roughly 3.25 Volts RMS) with engine running at 2000 RPM. Output voltage at cranking speed generally much lower.
Testing
- Clean and check connections.
- Can only be properly tested using an Oscilloscope trace should be a smooth sine wave.
- Check the voltage output using a digital multimeter.
- Resistance should be in the order of 12500 Ohms, but can vary from 700 to 1600.
- Remove from bellhousing, clean and examine sensor probe for mechanical damage.
Notes:
This probe is easily damaged mechanically, the probe tip projects into the bellhousing is mounted very close to the moving parts, hence is very vulnerable to a build up of debris.
The connecting plug is also very exposed to vibration, oil leaks and road dirt.