AutoCodesBuick – C1220 Buick

C1220 Buick 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 Buick 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.
AI answers can be wrong. Verify repairs with testing. Open full chat
Code Popularity 381
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Jul 13, 2023
💬 Need more help? Ask Coddy for instant answers — it's free!

Code C1220 Buick Description

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. The Electronic Brake Control Module monitors when the driver's foot is on the brake and locks the offset. The offset is locked when three out of the four inputs indicate the brake pedal is applied. The four inputs are brake pedal travel 1, brake pedal travel 2, master cylinder pressure sensor, and brake pedal position sensor. These inputs are used to determine the driver's braking intent which is used to control the amount of pressure applied to the wheels.
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.
OBDII Code C1220 Buick - Brake Pressure Sensor Supply Voltage Circuit High - AutoCodes.com
C1220 Buick Code - Brake Pressure Sensor Supply Voltage Circuit High

What are the Possible Causes of the DTC C1220 Buick?

  • 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 Buick?

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 Buick 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 C1220 Buick code?

Need more information on how to fix the C1220 Buick code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C1220 Buick code diagnosed by a professional: Find a repair shop in your area

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 C1220 Buick Code

1. What does the OBDII code C1220 mean on a Buick?

C1220 indicates a problem with the brake pressure sensor supply voltage circuit, specifically that the voltage is higher than the expected range.

2. What are common symptoms of the C1220 code on a Buick?

Common symptoms include the ABS warning light illuminated, reduced or malfunctioning ABS operation, and potentially a loss of traction control functionality.

3. What causes the C1220 code to appear on a Buick?

The code can be caused by a faulty brake pressure sensor, damaged wiring or connectors in the circuit, a malfunctioning ABS control module, or issues with the vehicle's power supply.

4. Can I drive my Buick with the C1220 code active?

While the vehicle may still be drivable, the ABS system may be disabled, increasing the risk of wheel lockup during hard braking. It’s best to address the issue promptly.

5. How is the C1220 code diagnosed on a Buick?

A technician will use a scan tool to read the code, inspect the brake pressure sensor and its wiring, measure circuit voltage, and test the ABS module to pinpoint the problem.

6. How do I fix the C1220 code on a Buick?

Repairs may include replacing a faulty brake pressure sensor, repairing or replacing damaged wiring or connectors, or reprogramming or replacing the ABS control module.

7. What tools are needed to troubleshoot the C1220 code on a Buick?

You’ll need an OBDII scan tool, a digital multimeter to check voltage and continuity, and possibly manufacturer-specific diagnostic tools for the ABS system.

8. Can a low battery cause the C1220 code on a Buick?

Yes, a weak or failing battery or charging system can cause electrical issues, including triggering the C1220 code.

9. How much does it cost to fix the C1220 code on a Buick?

The cost depends on the root cause. Replacing a brake pressure sensor typically costs $150–$300, while ABS module repairs or replacements can cost $500–$1,000 or more.

10. Will clearing the C1220 code solve the problem?

Clearing the code without addressing the underlying issue is only a temporary fix. The code will likely return if the root cause isn’t resolved.

Discuss the causes and fixes for C1220 Buick OBDII Code

Code C1220 Buick comments

No comments found for this page.

AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play