P0340 - Camshaft Position Sensor A Circuit Bank 1 or Single Sensor
P0340 is a generic powertrain diagnostic trouble code indicating Camshaft Position Sensor A Circuit Bank 1 or Single Sensor. It relates to the Ignition System / Misfire system.
DTC Breakdown (SAE J2012)
| System | Powertrain (P) |
| Type | Generic |
| Subsystem | Ignition System / Misfire |
| Fault Index | 40 |
| Standard | SAE J2012 / ISO 15031-6 |
What does diagnostic code P0340 mean?
The engine control module logged P0340 after detecting a circuit malfunction in the camshaft position sensor circuit, which is vital for calculating ignition and fuel timing.
Severity Level & Driveability Details
Severity: High
The engine may stall without warning while driving, presenting a severe safety hazard, and in some cases, the vehicle will not start at all.
Common Symptoms of P0340
- Engine cranking but failing to start (no start condition).
- Sudden engine stalling during operation.
- Rough idling, misfires, or engine hesitation.
- Check engine light illuminated.
Typical Causes for P0340
- Failed camshaft position sensor.
- Corroded connector pins or damaged wiring harness on the sensor.
- Damaged reluctor wheel teeth.
- Engine timing belt or chain that has jumped timing teeth.
Diagnostic and Troubleshooting Steps
Use an oscilloscope to check the sensor square-wave signal while cranking. If the signal is missing, check reference voltage (5V or 12V) and ground at the connector plug.
Typical Repairs and Fixes
- Replacing the failed camshaft position sensor.
- Repairing damaged sensor wiring harness.
- Replacing the timing chain/belt and tensioners.
- Replacing the damaged reluctor wheel.
Sensor Location & Parts Involved
The crankshaft sensor is typically near the flywheel or crank pulley, while the camshaft sensor is near the top of the cylinder head.
Clearing Code & Recurrence
Reset codes with a scan tool to verify the sensor signal is detected and active.
Emissions & Smog Inspection Impact
Misfires and improper fuel injector synchronization increase unburned tailpipe emissions.
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Related Diagnostic Codes
Sources & References
This diagnostic guide is compiled and verified against the following authority sources:
- NHTSA safety recall logs
- SAE J2012 standard guidelines
Frequently Asked Questions about P0340
What does the camshaft position sensor A circuit malfunction code P0340 mean?
The engine control module logged P0340 after detecting a circuit malfunction in the camshaft position sensor circuit, which is vital for calculating ignition and fuel timing.
Is it safe to drive with the camshaft position sensor A circuit malfunction code P0340 active?
No, a sensor fault poses a high stalling risk.
How much does it cost to repair a camshaft position sensor A circuit malfunction code P0340 fault?
A replacement sensor costs $40-$120. Labor to install the sensor is $80-$200. Total cost to resolve the fault is $150-$400.
What are the common causes of the camshaft position sensor A circuit malfunction code P0340?
Trigger conditions for the camshaft position sensor A circuit malfunction code P0340 include: Failed camshaft position sensor., Corroded connector pins or damaged wiring harness on the sensor., Damaged reluctor wheel teeth..
Can I clear the check engine light for camshaft position sensor A circuit malfunction code P0340?
Reset codes with a scan tool to verify the sensor signal is detected and active.
Will the camshaft position sensor A circuit malfunction code P0340 cause an inspection failure?
Misfires and improper fuel injector synchronization increase unburned tailpipe emissions.