P1391 Code - CMP or CKP Signal Intermittent Condition
Quick Answer
The P1391 diagnostic trouble code (DTC) indicates that there is an intermittent issue with the CMP (Camshaft Position Sensor) or CKP (Crankshaft Position Sensor) signal. Common causes include Faulty CMP or CKP sensor, Wiring or connector issues, Sensor alignment or mounting problems. 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
- P1391 indicates CMP or CKP Signal Intermittent Condition.
- Common causes
- Common causes include Faulty CMP or CKP sensor, Wiring or connector issues, Sensor alignment or mounting problems.
- 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 P1391 Description
The P1391 diagnostic trouble code (DTC) indicates that there is an intermittent issue with the CMP (Camshaft Position Sensor) or CKP (Crankshaft Position Sensor) signal. These sensors play a crucial role in the engine's operation by providing data to the engine control module (ECM) to determine the precise timing of the engine's ignition and fuel injection. When the ECM detects an intermittent signal from either sensor, it can lead to misfires, poor fuel economy, rough idling, and even stalling. This issue can significantly impact the vehicle's performance and drivability.
Common Causes of P1391
- Faulty CMP or CKP sensor
- Wiring or connector issues
- Sensor alignment or mounting problems
- ECM software or hardware issues
- Engine timing belt or chain problems
Symptoms of P1391
- Engine misfires
- Rough idling or stalling
- Decreased fuel efficiency
- Difficulty starting the engine
- Illuminated check engine light
How to Fix P1391
- Perform a visual inspection of the CMP and CKP sensors, wiring, and connectors for any visible damage or corrosion.
- Test the sensors using a multimeter to check for proper voltage and resistance values.
- Verify the alignment and mounting of the sensors to ensure they are positioned correctly.
- Scan the ECM for any stored fault codes and address any related issues.
- Replace any faulty sensors, repair damaged wiring or connectors, and reset the ECM to clear the code.
Cost to Fix P1391
The cost of repairing a P1391 code can vary depending on the specific cause of the issue and the make and model of the vehicle. On average, the repair costs for this issue can range from $100 to $300, including parts and labor. However, it's essential to consult with a professional mechanic to get an accurate estimate based on your vehicle's needs. Keep in mind that diagnostic time and labor rates can vary, so it's advisable to inquire about pricing beforehand.
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Code P1391 Information for Specific Makes
- P1391 Acura — G-Sensor Performance Problem
- P1391 Audi — Camshaft Position Sensor Bank 2 Short To Ground
- P1391 Buick — Wheel Speed Sensor 1 G-Sensor Circuit Performance
- P1391 Cadillac — Wheel Speed Sensor 1 G-Sensor Circuit Performance
- P1391 Chevrolet — Wheel Speed Sensor 1 G-Sensor Circuit Performance
- P1391 Chrysler — CMP Or CKP Signal Intermittent Condition
- P1391 Dodge — CMP or CKP Signal Intermittent Condition
- P1391 Ford — Glow Plug Circuit Low Input Bank 1
- P1391 GMC — Wheel Speed Sensor 1 G-Sensor Circuit Performance
- P1391 Honda — G-Sensor Performance Problem
- P1391 Isuzu — G-Sensor Performance Rough road sensor
- P1391 Jeep — CMP or CKP Signal Intermittent Condition
- P1391 Mitsubishi — Intermittent Loose Of Camshaft Position Or Crankshaft Position Sensor
- P1391 Saab — Cylinder 1 Misfire Detected Random Fuel Level Low
- P1391 Suzuki — G Sensor Rough Road Rationality
- P1391 Volkswagen — Camshaft Position Sensor Bank 2 Short To Ground
Frequently Asked Questions about P1391 Code
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