Worn or stretched timing chain, timing belt, or distributor drive gear causing the camshaft to lag or lead the crankshaft; Faulty camshaft position sensor or a damaged sensor reluctor wheel; Faulty crankshaft position sensor or a damaged crank reluctor wheel; Wiring damage, corrosion, or loose connectors in the cam or crank sensor circuits; Incorrectly installed distributor or camshaft during a prior repair, leaving the base timing off; PCM calibration issue or internal PCM fault, though this is the least common cause

DTC codes / GM codes / P1345

P1345 · GMCamshaft to Crankshaft Position Correlation Fault

Q: What does code P1345 mean?

Camshaft to Crankshaft Position Correlation Fault. P1345 on GM vehicles means the powertrain control module (PCM) has detected a mismatch between the camshaft position sensor signal and the crankshaft position sensor signal, so the two shafts are not rotating in the expected relationship. The PCM compares the two signals during cranking and running, and it sets this code when the correlation falls outside the calibrated window for a set number of engine cycles.

P1345 on GM vehicles means the powertrain control module (PCM) has detected a mismatch between the camshaft position sensor signal and the crankshaft position sensor signal, so the two shafts are not rotating in the expected relationship. The PCM compares the two signals during cranking and running, and it sets this code when the correlation falls outside the calibrated window for a set number of engine cycles.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyProfessional

AreaIgnition system and misfire

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms besides the warning light
Extended cranking before the engine starts or an intermittent no-start condition
Rough idle, misfire, or a stumble during acceleration as the PCM loses accurate sequential fuel and spark timing
Reduced engine power or limp-home operation if the PCM defaults to a backup timing strategy
Poor fuel economy and elevated emissions from incorrect injection timing
In some cases, a stall immediately after startup or when coming to a stop

Common causes, most likely first

Worn or stretched timing chain, timing belt, or distributor drive gear causing the camshaft to lag or lead the crankshaft
Faulty camshaft position sensor or a damaged sensor reluctor wheel
Faulty crankshaft position sensor or a damaged crank reluctor wheel
Wiring damage, corrosion, or loose connectors in the cam or crank sensor circuits
Incorrectly installed distributor or camshaft during a prior repair, leaving the base timing off
PCM calibration issue or internal PCM fault, though this is the least common cause

How to diagnose and fix it

Scan all modules and record freeze-frame data for P1345, then check for related cam and crank sensor codes before touching any parts
Inspect the camshaft and crankshaft sensor connectors and harnesses for chafing, corrosion, and loose pins, and verify reference voltage and ground at each sensor
Use a scan tool to compare cam and crank sensor signals or view cam retard/correlation data while cranking and running to confirm the mismatch is real
Check base engine timing mechanically by verifying the timing marks on the crank and cam, or by inspecting the distributor installation on engines that use one
Test the camshaft and crankshaft position sensors with a lab scope or manufacturer-specific resistance and signal tests, replacing only the sensor proven faulty
If timing components are worn or jumped, replace the timing chain or belt and associated tensioners and guides, then recheck correlation
Clear the code and perform a road test with the scan tool recording to confirm the correlation stays within specification and the code does not return

What P1345 really tells you about timing

A stretched timing chain on high-mileage GM engines is the most common root cause, and replacing only the cam sensor will not fix the correlation fault because the mechanical timing is already off
The code can set intermittently from a failing sensor that still produces a signal at idle but drops out under heat or vibration, so a cold pass on the scan tool does not prove the sensor is good
On engines with a distributor, an incorrectly stabbed distributor after a repair will set P1345 even with new sensors, so base timing and distributor alignment must be verified before parts are replaced
A weak or failing crankshaft position sensor can cause the PCM to lose the crank reference and report a cam correlation fault, so both signals must be scoped together rather than tested in isolation
P1345 does not always mean the engine will run poorly; some vehicles drive normally with only the light on, which leads owners to postpone a repair that can become a no-start or timing chain failure

Can I keep driving with P1345?

You can usually drive the vehicle to a shop for diagnosis, but avoid hard acceleration, towing, and long trips until the cause is confirmed. If the engine cranks but will not start, stalls, or runs very rough, stop driving and have it towed because a jumped timing chain can cause internal engine damage.

Tools that help

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Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.