AutoCodesGMC – P0340 GMC

P0340 GMC Code - Camshaft Position Sensor Circuit

Quick Answer

The Camshaft Position Sensor detects magnetic flux changes between the four narrow and wide tooth slots on the reluctor wheel. Common causes include Faulty Camshaft Position Sensor, Camshaft Position Sensor harness is open or shorted, Camshaft Position Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0340 GMC indicates Camshaft Position Sensor Circuit.
Common causes
Common causes include Faulty Camshaft Position Sensor, Camshaft Position Sensor harness is open or shorted, Camshaft Position Sensor circuit poor electrical connection.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code Popularity 45,247
How popular is this code, among other codes? Medium
Table of contents Created and updated by William Orellana on Aug 26, 2022
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Code P0340 GMC Description

The Camshaft Position Sensor detects magnetic flux changes between the four narrow and wide tooth slots on the reluctor wheel. The Camshaft Position Sensor provides a digital ON/OFF DC voltage of varying frequency for each camshaft revolution. The Engine Control Module (ECM) will recognize the narrow and wide tooth patterns to identify the camshaft position, or which cylinder is in compression, and which is in the exhaust. The information is then used to determine the correct time and sequence for fuel injection and ignition spark events.
The ECM also has a dedicated replicated Camshaft Position Sensor signal output circuit that may be used as an input signal to other modules for monitoring engine RPM.
The Diagnostic Trouble Code (DTC) will be set when the ECM does not receive a signal from the Camshaft Position Sensor during 200 engine revolutions.
OBDII Code P0340 GMC - Camshaft Position Sensor Circuit - AutoCodes.com
P0340 GMC Code - Camshaft Position Sensor Circuit

What are the Possible Causes of the DTC P0340 GMC?

  • Faulty Camshaft Position Sensor
  • Camshaft Position Sensor harness is open or shorted
  • Camshaft Position Sensor circuit poor electrical connection
  • Faulty starter motor
  • Starting system circuit
  • Dead (Weak) battery

How to Fix the DTC P0340 GMC?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

Code Tech Notes

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0340 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0340 GMC code?

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Information for Specific GMC Models

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0340 GMC Code

1. What are the common symptoms of OBDII code P0340 in a GMC vehicle?

The common symptoms of OBDII code P0340 in a GMC vehicle include engine misfires, rough idling, stalling, poor acceleration, and difficulty starting the engine.

2. What is the main cause of OBDII code P0340 in a GMC vehicle?

The main cause of OBDII code P0340 in a GMC vehicle is a faulty camshaft position sensor or issues with the camshaft position sensor circuit.

3. How can I diagnose the cause of OBDII code P0340 in my GMC vehicle?

To diagnose the cause of OBDII code P0340 in your GMC vehicle, you can use a scan tool to check for the code, visually inspect the camshaft position sensor and its wiring, and perform a continuity test on the sensor circuit.

4. Can a bad camshaft position sensor cause OBDII code P0340 in a GMC vehicle?

Yes, a bad camshaft position sensor can cause OBDII code P0340 in a GMC vehicle because the sensor is responsible for detecting the position of the camshaft and sending signals to the engine control module.

5. How can I repair OBDII code P0340 in my GMC vehicle?

To repair OBDII code P0340 in your GMC vehicle, you may need to replace the camshaft position sensor, repair any damaged wiring or connectors in the sensor circuit, and clear the error code using a scan tool.

6. Are there any DIY tips for fixing OBDII code P0340 in a GMC vehicle?

While fixing OBDII code P0340 in a GMC vehicle may require technical knowledge, DIY enthusiasts can attempt to replace the camshaft position sensor themselves by following a repair manual or online tutorials.

7. Can driving with OBDII code P0340 in a GMC vehicle cause further damage?

Continuing to drive with OBDII code P0340 in a GMC vehicle can potentially cause damage to other engine components or lead to more severe issues, so it is recommended to address the problem promptly.

8. Is resetting the check engine light enough to fix OBDII code P0340 in a GMC vehicle?

Simply resetting the check engine light without addressing the underlying issue causing OBDII code P0340 in a GMC vehicle will not fix the problem. It is essential to diagnose and repair the root cause of the code.

9. How much does it typically cost to fix OBDII code P0340 in a GMC vehicle at a repair shop?

The cost of fixing OBDII code P0340 in a GMC vehicle at a repair shop can vary depending on the labor rates and parts needed, but it may range from $100 to $300 or more.

10. Can a dirty camshaft position sensor cause OBDII code P0340 in a GMC vehicle?

Yes, a dirty or contaminated camshaft position sensor can cause OBDII code P0340 in a GMC vehicle as dirt or debris can interfere with the sensor's operation and affect its ability to detect the camshaft's position accurately.

Discuss the causes and fixes for P0340 GMC OBDII Code

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