Faulty intake camshaft position sensor; Damaged or chafed wiring in the sensor circuit; Corroded or loose electrical connector at the sensor; Contaminated or incorrectly gapped sensor reluctor wheel; Stretched timing chain or worn timing chain tensioner; Engine oil sludge or debris obstructing the sensor tip; Failed engine control module (ECM) driver circuit, though uncommon

DTC codes / GM codes / P1346

P1346 · GMIntake Camshaft Position (CMP) Sensor System Performance

Q: What does code P1346 mean?

Intake Camshaft Position (CMP) Sensor System Performance. P1346 on a GM vehicle means the engine computer has detected a performance problem with the intake camshaft position sensor circuit, typically a signal that does not match expected timing or is intermittent. The computer compares the intake camshaft position sensor signal to the crankshaft position sensor and sets this code when the relationship falls outside the programmed window.

P1346 on a GM vehicle means the engine computer has detected a performance problem with the intake camshaft position sensor circuit, typically a signal that does not match expected timing or is intermittent. The computer compares the intake camshaft position sensor signal to the crankshaft position sensor and sets this code when the relationship falls outside the programmed window.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Rough idle or intermittent misfire, especially when the engine is cold
Reduced engine power or a stumble during acceleration
Poor fuel economy or increased emissions
Hard starting or extended cranking before the engine fires
In rare cases, the engine may stall or enter limp mode

Common causes, most likely first

Faulty intake camshaft position sensor
Damaged or chafed wiring in the sensor circuit
Corroded or loose electrical connector at the sensor
Contaminated or incorrectly gapped sensor reluctor wheel
Stretched timing chain or worn timing chain tensioner
Engine oil sludge or debris obstructing the sensor tip
Failed engine control module (ECM) driver circuit, though uncommon

How to diagnose and fix it

Connect a scan tool and record freeze-frame data and any stored codes to confirm the fault conditions
Visually inspect the intake camshaft position sensor, its connector, and the wiring harness for damage or corrosion
Measure sensor resistance and check for a clean, consistent signal with an oscilloscope or multimeter
Verify the sensor reluctor wheel for damage, debris, or incorrect air gap
Check base engine timing and inspect the timing chain for stretch or wear
Perform a voltage drop test on the sensor ground and power circuits to rule out wiring resistance
Replace the intake camshaft position sensor only after confirming the circuit and mechanical timing are sound

What a P1346 often hides

A stretched timing chain can set P1346 without any sensor fault, so always verify mechanical timing before replacing parts.
Oil sludge or debris on the sensor tip is a common cause that is easily overlooked during a quick visual inspection.
Intermittent wiring faults may only appear when the engine is hot or vibrating, so wiggle-test the harness while monitoring live data.
The code can be set by a poor connection at the sensor pigtail even when the sensor itself tests good on the bench.
Replacing the sensor without addressing a worn reluctor wheel or timing chain will lead to a repeat failure.

Can I keep driving with P1346?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy acceleration, towing, or long trips until the fault is diagnosed. If the engine runs rough, stalls, or loses power, stop driving and arrange a tow to prevent further 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.