P0558
DTC P0556, P0557, or P0558
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0556
- Brake Booster Pressure Sensor Performance
DTC P0557
- Brake Booster Pressure Sensor Circuit Low Voltage
DTC P0558
- Brake Booster Pressure Sensor Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The power brake booster vacuum sensor monitors the vacuum pressure in the brake booster. The ECM compares the readings of the engine vacuum with the brake booster vacuum.
Conditions for Running the DTC
P0556
* Engine is running and vehicle speed is above 40 km/h (25 mph).
* No TPS sensor DTCs are present.
* The transmission is in drive.
P0557 or P0558
Engine running.
Conditions for Setting the DTC
P0556
The ECM detects the vacuum level between the engine and brake booster is greater than 6kPa.
P0557
The ECM detects a short to ground or open in either the sensor signal circuit or the brake booster vacuum sensor.
P0558
The ECM detects an open with the sensor ground or a short to voltage in either the signal circuit or the brake booster vacuum sensor.
Action Taken When the DTC Sets
* DTCs P0556, P0557 or P0558 are Type B DTCs.
* ABS warning indicator is illuminated.
Conditions for Clearing the DTC
DTCs P0556, P0557 or P0558 are Type B DTCs.
Reference Information
Schematic Reference
Hydraulic Brake Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Brake Assist System Description and Operation (Brake Assist System Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the brake booster vacuum sensor.
2. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal 2 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 1 and ground.
• If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
• If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Verify the scan tool ECM Brake Booster Pressure Sensor parameter is less than 0.15 volt.
• If greater than the specified range, test the signal circuit terminal for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3A fused jumper wire between the signal circuit terminal 3 and the 5-volt reference circuit terminal 1. Verify the scan tool ECM Brake Booster Pressure Sensor parameter is greater than 4.75 volts.
• If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
6. If all circuits test normal, test or replace the brake booster pressure sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Power Brake Booster Vacuum Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming