C1239 GMC Code - Brake Pressure Sensor 1/2 Correlation
Quick Answer
The Electronic Brake Control Module uses inputs from the Electronic Brake Control Brake Pedal Position Sensor to determine when the brake is applied and how much force is used. Common causes include Faulty Electronic Brake Control Module (EBCM), Electronic Brake Control Module harness is open or shorted, Electronic Brake Control Module 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
- C1239 GMC indicates Brake Pressure Sensor 1/2 Correlation.
- Common causes
- Common causes include Faulty Electronic Brake Control Module (EBCM), Electronic Brake Control Module harness is open or shorted, Electronic Brake Control Module 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 C1239 GMC Description
Brake pressure sensor information is communicated from the Electronic Brake Control Module (EBCM) to the Hybrid Control Processor (HCP). This information is used to schedule regenerative braking and engine autostops.
The Diagnostic Trouble Code (DTC) will be set when the Engine Control Module (ECM) detects a corrupted data message from the Electronic Brake Control Module.
What are the Possible Causes of the DTC C1239 GMC?
- Faulty Electronic Brake Control Module (EBCM)
- Electronic Brake Control Module harness is open or shorted
- Electronic Brake Control Module circuit poor electrical connection
- Faulty Starter/Generator Control Module
How to Fix the DTC C1239 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 C1239 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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Information for Specific GMC Models
- C1239 2014 GMC Sierra — Brake Pressure Sensor 1/2 Correlation
- C1239 2015 GMC Sierra — Brake Pressure Sensor 1/2 Correlation
- C1239 2016 GMC Sierra — Brake Pressure Sensor 1/2 Correlation
- C1239 2017 GMC Sierra — Brake Pressure Sensor 1/2 Correlation
- C1239 2018 GMC Sierra — Brake Pressure Sensor 1/2 Correlation
Frequently Asked Questions about C1239 GMC Code
What does the OBDII code C1239 mean for GMC vehicles?
C1239 indicates a Brake Pressure Sensor 1/2 Correlation issue, where the readings from the brake pressure sensors do not match or fall within expected parameters.
What are the common symptoms of code C1239 in GMC vehicles?
Symptoms include the ABS warning light turning on, reduced braking performance, or activation of fail-safe braking modes.
What causes the C1239 code to appear in GMC vehicles?
Common causes include faulty brake pressure sensors, wiring or connector issues, or problems with the ABS control module.
Can I drive my GMC vehicle with code C1239?
It’s not recommended to drive with this code active, as it may affect braking performance and compromise safety.
How do I diagnose code C1239 on my GMC vehicle?
Start by scanning the ABS system for codes, inspecting brake pressure sensor wiring and connectors for damage, and testing the sensors for proper operation using a multimeter or diagnostic tool.
How can I fix code C1239 in GMC vehicles?
Repairs may involve replacing one or both brake pressure sensors, repairing damaged wiring or connectors, or recalibrating the ABS module.
Do I need to replace both brake pressure sensors for C1239?
Not necessarily. Only the faulty sensor or wiring causing the mismatch needs replacement, unless both sensors are confirmed to be malfunctioning.
How much does it cost to repair code C1239 on a GMC vehicle?
Repair costs vary, but replacing a brake pressure sensor typically costs $100-$300, while ABS module repairs or replacements may be more expensive.
Can a dead battery trigger code C1239 on a GMC vehicle?
A dead or weak battery can sometimes cause electrical issues, but this code is usually related to sensor or wiring faults.
Will clearing the code C1239 fix the problem permanently?
No, clearing the code will only remove the warning temporarily. The underlying issue must be addressed to prevent the code from reappearing.
Discuss the causes and fixes for C1239 GMC OBDII Code
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