P0338 GMC Code - Crankshaft Position Sensor Circuit High Duty Cycle
Quick Answer
The Crankshaft Position Sensor (CKP) also known as the crank position sensor is an electronic device used in an engine to record the rate at which the crankshaft is spinning. Common causes include Faulty crankshaft position sensor, Crankshaft position sensor harness is open or shorted, Crankshaft 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
- P0338 GMC indicates Crankshaft Position Sensor Circuit High Duty Cycle.
- Common causes
- Common causes include Faulty crankshaft position sensor, Crankshaft position sensor harness is open or shorted, Crankshaft 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.
Code P0338 GMC Description
When the engine is running, the high and low parts of the teeth cause the gap with the sensor to change. The changing gap causes the magnetic field near the sensor to change. The change in the magnetic field cause the voltage from the sensor to change.
What are the Possible Causes of the DTC P0338 GMC?
- Faulty crankshaft position sensor
- Crankshaft position sensor harness is open or shorted
- Crankshaft position sensor circuit poor electrical connection
- Signal plate may be damage
- Starter motor may be faulty
- Starting system circuit
- Dead or weak battery
How to Fix the DTC P0338 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.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0338 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.
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Frequently Asked Questions about P0338 GMC Code
1. What are the common symptoms of OBDII code P0338 in a GMC vehicle?
- Common symptoms include rough idling, engine misfires, stalling, decreased fuel efficiency, and difficulty starting the engine.
2. What can cause the OBDII code P0338 to trigger in a GMC vehicle?
- The code P0338 is often triggered by a faulty crankshaft position sensor, damaged wiring or connectors related to the sensor, or issues with the sensor circuit's voltage.
3. How does a high duty cycle in the crankshaft position sensor circuit contribute to code P0338 in a GMC vehicle?
- A high duty cycle in the crankshaft position sensor circuit can disrupt the sensor's ability to accurately detect the crankshaft's position, leading to the triggering of code P0338.
4. Can a faulty crankshaft position sensor cause code P0338 in a GMC vehicle?
- Yes, a faulty crankshaft position sensor is a common cause of code P0338 as it can send incorrect signals or fail to provide data to the engine control module.
5. How can I diagnose and repair code P0338 related to the crankshaft position sensor in my GMC vehicle?
- Diagnosis involves checking the sensor's wiring, connectors, and voltage levels. Repair may involve replacing the crankshaft position sensor, repairing damaged wiring, or addressing issues with the sensor circuit.
6. Is it safe to continue driving with OBDII code P0338 present in a GMC vehicle?
- It is not recommended to continue driving with code P0338 present, as it can lead to engine performance issues and potential further damage if left untreated.
7. Can a DIY enthusiast fix the OBDII code P0338 related to the crankshaft position sensor in a GMC vehicle?
- Depending on your experience and tools available, DIY enthusiasts may be able to fix code P0338 by replacing the crankshaft position sensor or addressing wiring/connectivity issues.
8. Are there any preventive measures to avoid triggering code P0338 in a GMC vehicle?
- Regularly inspecting and maintaining the crankshaft position sensor, as well as ensuring the sensor's wiring and connectors are in good condition, can help prevent code P0338 from being triggered.
9. How long does it typically take to repair OBDII code P0338 in a GMC vehicle?
- The repair time for code P0338 can vary depending on the exact cause of the issue, but it generally takes around 1-2 hours for a professional mechanic to diagnose and fix the problem.
10. Will resetting the OBDII system clear code P0338 in a GMC vehicle?
- Resetting the OBDII system may temporarily clear the code, but if the underlying issue such as a faulty crankshaft position sensor or wiring problem persists, the code is likely to reappear.
Discuss the causes and fixes for P0338 GMC OBDII Code
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I have replaced the crank shaft position sensor and the truck still won't start. I have also replaced the ignition coil any suggestions? I have also put in a brand new battery and a starter.
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If you have only the P0338 code and you have already replace the Crankshaft Position Sensor, then the next step is to check the flywheel for damage (sensor is not reading the flywheel) or the wires from the sensor to the Powertrain Control Module (PCM).
I have checked a national database of repairs and there are reports about anything else triggering the P0338 code.
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