Crankshaft Position - Camshaft Position Correlation

What it means

This is a GMC manufacturer-specific code, and the same number can mean something different on other makes. On Vortec engines with a distributor, camshaft position is read by a sensor inside the distributor, and the computer sets this code when the cam signal does not fall in the right place relative to the crank signal. Most often it means the distributor needs to be aligned with a scan tool.

Models covered: GMC models with Vortec V6/V8 engines and a distributor, mainly around 1996–2004 (e.g. Sierra, Yukon, Savana).

Related codes: P0016P0340P0335P0300P0342

Symptoms4

• Check engine light on; the vehicle may still drive normally if the offset is small.
• Stumble or misfire under load or when towing if the offset is large.
• Slower than usual starting at times.
• Burn marks or unusual wear inside the distributor cap.

Possible causes6

• Incorrect distributor alignment after it was removed for another repair or replaced.
• A distributor hold-down bolt that is not tight, letting it turn with vibration.
• Wear in the distributor gear or internal bushing.
• A faulty camshaft sensor inside the distributor or its connector.
• A timing chain stretched with high mileage (less common).
• A faulty crankshaft position sensor.

How to diagnose5

1. Check the service history: was the distributor recently removed or replaced?
2. Read the cam retard value on a GM-capable scan tool at steady rpm and compare it with the manufacturer specification.
3. Confirm the distributor is tight and its shaft has no side play.
4. Inspect the inside of the cap and the rotor for crossfire marks.
5. If the value keeps drifting or cannot be set, check the distributor gear and timing chain condition.

How to fix5

1. Tighten the distributor hold-down bolt.
2. Align the distributor by turning it gradually while watching the retard value until it is within specification.
3. Replace the cap and rotor if they show burn marks.
4. Replace the distributor if the gear or bushing is worn, then align it.
5. Replace a stretched timing chain if confirmed, then clear the codes and watch that they stay clear.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

Alignment alone is the cheapest, a new distributor raises the cost, and a timing chain is the highest. On a Savana, labor can be higher because engine access in the van body is harder.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions