1996 LT1 P0336 Crank / Distributor Correlation Diagnosis
1996 LT1 P0336 diagnosis separating the crank sensor from timing-chain wear, distributor indexing, reluctor problems and other mechanical correlation faults.
It is a correlation check, not a simple crank-sensor verdict.
The PCM compares the crankshaft-position signal with the distributor high- and low-resolution signals. The 1996 crank sensor is used for crank-velocity/misfire information; GM states it is not used to command spark or fueling.
P0336 does not prove the crank sensor.
Factory diagnostic aids also identify poor connections, timing-chain/gear wear, distributor drive backlash or indexing, crank reluctor damage/installation and front-cover/sensor contact as possible causes.
CKP:Lo Resolution Angle matters.
On a sound, correctly indexed engine this value should be near zero. The 1996 DTC logic monitors a deviation outside -10° to +7° while still within -21° to +51°. Use the exact diagnostic conditions before judging the number.
- Save freeze-frame/failure records and check whether P1371 or another distributor-reference fault is also present.
- Compare crankshaft RPM and engine speed under appropriate conditions; do not condemn a sensor from a hard-acceleration snapshot.
- Inspect CKP sensor connection and physical relationship to the reluctor.
- Evaluate CKP:Lo Resolution Angle. A value that shifts positive on acceleration and negative on deceleration can point toward timing-chain/gear wear.
- If recent front-cover/distributor work occurred, verify reluctor position and distributor drive indexing before replacing electronics.
- Repair the proven cause and reproduce the original RPM/load condition.
Mechanical indexing deserves extra attention.
Cam/timing-set changes, front-cover work, distributor replacement and engine swaps can change the probability of an indexing/correlation problem. Diagnose what is installed now.
AFTER THE FAILURE IS PROVEN
Use the proven failed branch—not the original symptom—to choose the replacement. Go from diagnosis to the Parts Verdict →