P083

Circuit Description

This diagnostic test checks for 24X signal at a logic high condition. The fault could be induced by the failure of either Crankshaft Position A or B Sensor input signal to the Ignition Control Module. Under such a condition, the Ignition Control Module would force the 24X signal high. This test also checks for 24X shorted to battery externally. If either condition is met Code P083 is set.

Test Condition(s)

1. Code P035 is not set.
2. Engine speed greater than 496 RPM and less than 1200 RPM.
3. Number of CAM pulses since key 'ON' is 7 or greater.
4. Ignition control not in bypass.

Failure Condition(s)

24X signal at a logic HI and no 24X reference pulses received since last CAM pulse.

Action Taken

PCM turns 'ON' the 'SERVICE ENGINE SOON' MIL.

Notes on Fault Tree

1. Checking if Code P035 is set because a REF LO problem can cause other ignition problems.
2. If the engine stalls, the problem is with crankshaft position 'B' sensor because the engine will remain running with only one crankshaft sensor.
3. Checking crankshaft position 'B' sensor and circuitry for opens or shorts. The correct resistance should be between 800 ohms and 1600 ohms.
4. Checking if CKT 1729 or CKT 1730 is shorted to ground. If CKT is shorted to ground it will measure less than 100 ohms.
5. If the sensor is able to produce a DC voltage greater than 0.25 volt the sensor is OK.
6. If engine stalls, the problem is with crankshaft position A sensor. If the engine remains running, the ignition control module or CKT 647 are shorted high.
7. Checking crankshaft position A sensor and circuitry for opens or shorts. The correct resistance should be between 800 ohms and 1600 ohms.
8. Checking if CKT 1727 or CKT 1728 is shorted to ground. If the CKT is shorted to ground it will measure less than 100 ohms.
9. If the sensor is able to produce a DC voltage greater than 0.25 volt the sensor is OK.
10. Checking if CKT 647 is shorted high or if the ICM is keeping it high. If you measure greater than 0 Hz the ICM and CKT 647 are OK, the fault is intermittent.