P1639 Chevrolet Code - PCM 5 Volt Reference Voltage Circuit Condition
Quick Answer
The Powertrain Control Module (PCM) uses the 5-volt reference 2 circuit as a sensor feed for the A/C refrigerant pressure sensor. Common causes include Sensor using 5 volt reference line shorted to ground, Circuit short to ground. 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
- P1639 Chevrolet indicates PCM 5 Volt Reference Voltage Circuit Condition.
- Common causes
- Common causes include Sensor using 5 volt reference line shorted to ground, Circuit short to ground.
- 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 P1639 Chevrolet Description
What are the Possible Causes of the DTC P1639 Chevrolet?
- Sensor using 5 volt reference line shorted to ground
- Circuit short to ground
How to Fix the DTC P1639 Chevrolet?
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 P1639 Chevrolet 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 P1639 Chevrolet Code
1. What are common symptoms of OBDII code P1639 in a Chevrolet vehicle?
- Common symptoms include engine stalling, rough idle, decreased fuel efficiency, and issues with vehicle acceleration.
2. What causes the P1639 code to trigger in a Chevrolet car or truck?
- The code is typically triggered by a malfunction in the PCM 5-volt reference voltage circuit, which may be caused by wiring issues, a faulty PCM, or a short circuit.
3. How serious is the P1639 code in a Chevrolet vehicle?
- The P1639 code can potentially lead to engine performance issues and should be addressed promptly to avoid further damage to the vehicle.
4. How can I diagnose the PCM 5-volt reference voltage circuit condition in my Chevrolet to resolve the P1639 code?
- Diagnosing the issue may involve checking the wiring harness for damage, testing the PCM for faults, and using a multimeter to measure voltage at various points in the circuit.
5. Can I fix the PCM 5-volt reference voltage circuit issue triggering the P1639 code myself?
- While some DIY enthusiasts may be able to address the issue, it is recommended to consult a professional mechanic with experience in diagnosing and repairing OBDII codes like P1639.
6. Is it safe to drive my Chevrolet with the P1639 code present?
- It is not recommended to drive the vehicle with the P1639 code active, as it can lead to potential engine performance issues and further damage if left unresolved.
7. How much does it typically cost to repair the PCM 5-volt reference voltage circuit issue causing the P1639 code in a Chevrolet?
- Repair costs can vary depending on the exact cause of the issue and labor rates in your area, but it is advisable to budget for potential PCM replacement or wiring repairs.
8. Can the P1639 code be intermittent in a Chevrolet vehicle?
- Yes, the P1639 code can sometimes be intermittent, making it important to address the underlying issue even if the symptoms temporarily disappear.
9. Will resetting the OBDII system clear the P1639 code in my Chevrolet?
- Resetting the system may temporarily clear the code, but it is likely to return if the underlying issue with the PCM 5-volt reference voltage circuit is not resolved.
10. Are there any recalls or technical service bulletins related to the P1639 code in Chevrolet vehicles?
- It is advisable to check with a Chevrolet dealership or online databases for any recalls or technical service bulletins related to the P1639 code in your specific vehicle model.
Discuss the causes and fixes for P1639 Chevrolet OBDII Code
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i HAVE A 2002 CHEVY SILVERADO THAT WAS GIVING A P1639 CODE. THE TRUCK WAS RUNNING ROUGH IDLING ABOUT 400RPMS HIGHER THAN NORMAL AND SURGING. IT WOULD CUT OUT AND APPEAR TO HAVE ERATIC SHIFTING. AFTER SEVERAL DAYS OF CHECKING A/C REFRIDGERANT PRESSURE SENSORS, FUEL TANK PRESSURE SENSORS TPS SENSOR I FINALLY FOUND THAT THE PCM HAD WATER UNDER THE PLUG AND WAS SHORTING THE 5 VOLT REFERENCE. I HAVE YET TO SEE A POST REGARDING WATER IN THE HARNESS FOR THIS CODE AND WANTED TO POST FOR THOSE THAT ARE STRUGGLING WITH THIS CODE. EVERYONE SAYS THIS CODE SHOULDNT EFFECT THE VEHICLES PERFORMANCE, HOG WASH. TO CORRECT, I BLEW THE PINS OUT WITH COMPRESSED AIR AND SPRAYED WITH ELECTRICAL CONTACT CLEANER. I THEN COATED THE PINS WITH DIELECTRIC LUBE AND REINSERTED THE PLUG HARNESS INTO THE PCM. PROBLEM SOLVED.
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