P0340 on Cadillac: How to Diagnose & Fix
Camshaft Position Sensor Circuit Malfunction
1 Cadillac model · 1 documented issue · 1 critical · $400-$1,000 repair
P0340 on Cadillac by model: symptoms, diagnosis and fix
The 1994-1996 Fleetwood uses the LT1 V8 with the Optispark distributor mounted at the front of the engine behind the water pump. Water intrusion and internal component failure cause no-start conditions and misfires.
Common Symptoms
- No start
- Rough idle
- Misfire
- Stalling in rain
- Hard starting
How to Fix
Sources for this issue (1)
P0340 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0340 mean on a Cadillac?
P0340 stands for "Camshaft Position Sensor Circuit Malfunction." This code means the engine computer lost or received an erratic signal from the camshaft position sensor. That sensor tells the computer the exact position and speed of the camshaft, which it uses together with the crankshaft sensor to time fuel injection and spark precisely. When the camshaft signal is missing, intermittent, or out of range, the computer sets P0340. Symptoms often include hard starting, stalling, rough running, or a no-start because the engine can't time itself correctly. On Cadillac it is documented across 1 model: Fleetwood.
What are the most common causes of P0340?
The most common causes of P0340 are: Failed camshaft position sensor, Corroded or loose sensor connector, Damaged or shorted sensor wiring, Bad reluctor/tone ring on the camshaft, Loose timing chain/belt or jumped timing, Metal debris or oil contamination on the sensor tip, Poor sensor power or ground supply, Faulty PCM/ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P0340 on a Cadillac?
Published repair estimates on Cadillac range from $400 to $1,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.