AutoCodes – GMC – P15C5 GMC

P15C5 GMC Code - Engine Coolant Bypass Valve Position Sensor Performance - Unexpected Position Change Detected

Quick Answer

The passenger compartment heater coolant control valve regulates the engine coolant flow into the cabin heater loop depending on engine coolant temperature and ambient temperature conditions. Common causes include Faulty Engine Coolant Bypass Valve Position Sensor, Engine Coolant Bypass Valve Position Sensor harness is open or shorted, Engine Coolant Bypass Valve 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: P15C5 GMC indicates Engine Coolant Bypass Valve Position Sensor Performance - Unexpected Position Change Detected.
Common causes: Common causes include Faulty Engine Coolant Bypass Valve Position Sensor, Engine Coolant Bypass Valve Position Sensor harness is open or shorted, Engine Coolant Bypass Valve 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 1,183

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jan 03, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P15C5 GMC Description

The passenger compartment heater coolant control valve regulates the engine coolant flow into the cabin heater loop depending on engine coolant temperature and ambient temperature conditions. The passenger compartment heater coolant control valve has two positions: ByPass or Link. In the ByPass position, the coolant in the engine loop and heater loop are separated and in the link position the coolant circulates through both loops. The valve movement is controlled by a PWM signal. A 50% duty cycle is a normal duty cycle. A 75% duty cycle represents a valve commanded to the link position. A 25% duty cycle represents a valve commanded to the ByPass position. The passenger compartment heater coolant control valve uses an internal position sensor that sends a signal to the hybrid powertrain control module to determine the valve position.
When the engine coolant temperature heats up, a valve learn procedure takes place. The hybrid powertrain control module 2 commands the valve to the link position and records the voltage coming back from the position sensor. Then the hybrid powertrain control module 2 commands the valve back to the bypass position and records the voltage coming back from the position sensor. The voltage values in both the link and bypass positions must fall within calibrated ranges.

OBDII Code P15C5 GMC - Engine Coolant Bypass Valve Position Sensor Performance - Unexpected Position Change Detected - AutoCodes.com — P15C5 GMC Code - Engine Coolant Bypass Valve Position Sensor Performance - Unexpected Position Change Detected

What does this mean?

What are the Possible Causes of the DTC P15C5 GMC?

Faulty Engine Coolant Bypass Valve Position Sensor
Engine Coolant Bypass Valve Position Sensor harness is open or shorted
Engine Coolant Bypass Valve Position Sensor circuit poor electrical connection

How to Fix the DTC P15C5 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 P15C5 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 P15C5 GMC code?

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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 P15C5 GMC Code

1. What are common symptoms of OBDII code P15C5 in a GMC vehicle?

- Common symptoms include engine overheating, decreased fuel efficiency, and a potential decrease in engine performance.

2. What can cause the OBDII code P15C5 to trigger in a GMC vehicle?

- The code can be triggered by a faulty engine coolant bypass valve position sensor, wiring issues, or a malfunction in the engine control module.

3. How can I diagnose the cause of OBDII code P15C5 in my GMC vehicle?

- A professional diagnostic scan tool can help pinpoint the issue by reading the code and providing data on the engine coolant bypass valve position sensor's performance.

4. Is it safe to continue driving with OBDII code P15C5 present in a GMC vehicle?

- It is not recommended to continue driving with this code present, as it can lead to potential engine damage and overheating issues.

5. What is the typical repair process for resolving OBDII code P15C5 in a GMC vehicle?

- The typical repair process involves inspecting and potentially replacing the engine coolant bypass valve position sensor, checking and repairing any damaged wiring, and clearing the code from the engine control module.

6. Can I attempt to reset OBDII code P15C5 in my GMC vehicle using a simple OBDII scanner?

- While you can attempt to reset the code using an OBDII scanner, it is crucial to address the underlying issue causing the code to prevent further damage to the engine.

7. Are there any preventive maintenance tips to avoid OBDII code P15C5 in a GMC vehicle?

- Regularly checking and maintaining the engine coolant system, including the bypass valve and its sensor, can help prevent issues that may trigger this code.

8. How much does it typically cost to repair OBDII code P15C5 in a GMC vehicle?

- The cost of repairs can vary depending on the extent of the issue, but it may involve replacing the sensor and addressing any related wiring problems, costing a few hundred dollars on average.

9. Can a DIY enthusiast with automotive knowledge fix OBDII code P15C5 in a GMC vehicle?

- While some DIY enthusiasts may be able to tackle this repair, it is recommended to seek professional help to ensure the issue is diagnosed accurately and resolved effectively.

10. Does resolving OBDII code P15C5 require resetting the engine control module in a GMC vehicle?

- Yes, after addressing the underlying issue causing the code, it is important to clear the code and reset the engine control module to ensure proper operation and to prevent the code from reoccurring.