3-12
04/14/2009 NP10-V8JLR: AJ133 5.0-Liter DFI V8 Engine
Technical Training
Crankshaft Position Sensor
Engine Management System
The reluctor is manufactured to have a ‘tooth’ pattern
based on 60 – 2 pattern, where there are 58 teeth in total
at 6° intervals. The two teeth are removed to provide a
hardware reference mark, with a centerline that is 21°
BTDC on cylinder 1, RH bank. The signal voltage can be as low as 0.1V at low engine
speeds and up to 100V at high engine speeds. The ECM
does not react to the output voltage (unless the voltage is
extremely low or high); instead it measures the time
intervals between each pulse (signal frequency).
Safety Precautions CAUTIONS:
• Before installing the CKP sensor, check that no ferrous material has been attracted to
the device by its internal magnet.
• Ensure that the air gap is correct.
• Due to the location and orientation of the sensor, ensure that it is not damaged during
engine installation or by any debris that
may be picked up from the road. Failure Modes
• Sensor assembly loose
• Incorrect air gap – Nominal air gap 1.5mm (This is normally pre-set unless there is damage to the
mounting)
• Short/open circuit
• Mounting and integrity of the sensor
• Water/coolant ingress within connector
• Inability of the ECM to detect the software reference point
• Ferrous contamination of CKP sensor pin/reluctor
Failure Symptoms
• Engine will start picking up a signal from the CMP sensors (long crank time)
• Default 3000rpm (limp home mode)
REFERENCE EDGE
S
ENS OR OUTPUT
ECM INTERNAL
COMPARATOR OUTPUT 0V
MISSING TEETH
NP10V8095
