C1220 GMC Code - Brake Pressure Sensor Supply Voltage Circuit High
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
- C1220 GMC indicates Brake Pressure Sensor Supply Voltage Circuit High.
- 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 C1220 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 C1220 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 C1220 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 C1220 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
- C1220 2014 GMC Sierra — Brake Pressure Sensor Supply Voltage Circuit High
- C1220 2015 GMC Sierra — Brake Pressure Sensor Supply Voltage Circuit High
- C1220 2016 GMC Sierra — Brake Pressure Sensor Supply Voltage Circuit High
- C1220 2017 GMC Sierra — Brake Pressure Sensor Supply Voltage Circuit High
- C1220 2018 GMC Sierra — Brake Pressure Sensor Supply Voltage Circuit High
Frequently Asked Questions about C1220 GMC Code
1. What does the OBDII code C1220 mean on a GMC vehicle?
C1220 indicates a "Brake Pressure Sensor Supply Voltage Circuit High," meaning the brake pressure sensor is detecting a voltage higher than the expected range.
2. What are the common symptoms of code C1220 in a GMC vehicle?
Symptoms may include the ABS warning light illuminating, loss of ABS functionality, reduced braking performance, or a soft brake pedal feel.
3. What causes the C1220 code to appear in GMC vehicles?
Common causes include a faulty brake pressure sensor, damaged wiring or connectors, a malfunctioning ABS control module, or issues with the vehicle’s electrical system.
4. Can I still drive my GMC vehicle with a C1220 code?
While the vehicle may still be drivable, it is not recommended as the ABS system may not function properly, increasing the risk of reduced braking performance in emergencies.
5. How is the C1220 code diagnosed?
A technician will use a scan tool to confirm the code, inspect the brake pressure sensor and related wiring, check for proper voltage supply, and test the ABS control module for faults.
6. Can a bad ABS control module cause a C1220 code?
Yes, a malfunctioning ABS control module can cause incorrect voltage readings and trigger the C1220 code.
7. How do you fix the C1220 code on a GMC vehicle?
Repairs may include replacing the brake pressure sensor, repairing or replacing damaged wiring, cleaning corroded connectors, or, in some cases, replacing the ABS control module.
8. What tools are needed to troubleshoot the C1220 code?
Tools like an OBDII scanner, multimeter, and possibly a wiring diagram for the ABS system are typically required for diagnosis.
9. Can a low battery voltage cause the C1220 code on a GMC?
While unlikely, low system voltage could affect sensor readings and should be checked during the diagnostic process.
10. What should I do if the C1220 code reappears after repairs?
If the code reappears, recheck the wiring and connections, ensure the replacement parts are functioning correctly, and verify the ABS module is working properly.
Discuss the causes and fixes for C1220 GMC OBDII Code
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