Quick Diagnosis Guide
Meaning: Code P0340 indicates that the vehicle's onboard computer (ECU) has registered a fault in the powertrain (p) circuits.
Can I still drive? No, the vehicle may stall, fail to start, or enter limp-home mode because the engine computer cannot sync injector firing and spark timing with the pistons.
What does the P0340 code mean?
Diagnostic Trouble Code (DTC) P0340 stands for Camshaft Position Sensor Circuit Malfunction. This is a generic OBD-II trouble code indicating that the ECU has detected system performance parameters that fall outside normal calibrated tolerances.
When this code is logged, the ECU illuminates the dashboard check engine light and triggers a freeze frame record of engine sensor values to help diagnose the issue.
Common Symptoms of Code P0340
Depending on the vehicle make and driving conditions, you may observe the following symptoms:
- Check Engine Light on
- Engine cranks but will not start
- Intermittent stalling or engine stumbling
- Severe drop in engine power
What causes the P0340 fault code?
Root causes for a P0340 code typically include:
- Potential Cause 1: Failed Camshaft Position (CMP) Sensor
- Potential Cause 2: Damaged or corroded CMP sensor wiring connector
- Potential Cause 3: Weak or discharged car battery
- Potential Cause 4: Broken timing chain/belt teeth
Repair Database Status
No verified vehicle-specific workshop fix is currently logged in our mobile mechanic database for this code. Refer to the diagnostic checklist below to isolate the fault.
Step-by-Step Diagnostic & Inspection Checklist
To inspect and troubleshoot a P0340 code, mechanics follow these validation steps:
- Step 1: Scan codes with OBDAssistant. Check if crankshaft sensor codes (P0335) are also present.
- Step 2: Check wiring connector on camshaft sensor for loose pins.
- Step 3: Test CMP sensor resistance or output voltage signal.
Estimated Repair Cost Band
$80 - $250. CMP sensors are typically inexpensive and mounted accessibly on the cylinder head.
Note: Repair estimates vary based on vehicle make, model, local labor rates, and whether you require a full parts replacement.
Related Trouble Codes
If your scan tool registers other codes, check out these related guides:
Frequently Asked Questions
Occasionally, the ECU can run on crankshaft backup maps, but it will have long starting cranks and very poor performance.