P0557
DTC P0556, P0557, or P0558
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions 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 brake booster vacuum sensor monitors the pressure in the brake booster. The engine control module supplies a 5 V reference and a low reference circuit to the brake booster vacuum sensor. The vacuum sensor supplies a voltage signal in relation to the pressure in the brake booster to the engine control module.
Conditions for Running the DTC
P0556
Engine running.
P0557 or P0558
Ignition ON.
Conditions for Setting the DTC
P0556
The engine control module detects brake booster vacuum as being less than the intake manifold vacuum for more than 100 ms.
P0557
The engine control module detects less than 0.04 V on the brake booster sensor signal circuit for more than 12.5 ms.
P0558
The engine control module detects greater than 4.89 V on the brake booster sensor signal circuit for more than 12.5 ms.
Action Taken When the DTC Sets
DTCs P0556, P0557 or P0558 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0556, P0557 or P0558 are Type B DTCs.
Reference Information
Schematic Reference
Hydraulic Brake Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Brake Assist System Description and Operation Brake Assist System
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B19B Brake Booster Vacuum Sensor. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the low reference circuit terminal 2 and ground.
• If 10 ohms or greater
1. Disconnect the harness connector X1 at the K20 Engine Control Module.
2. Test for less than 2 ohms in the low reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.
• If less than 10 ohms
3. Ignition ON.
4. Test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground.
• If less than 4.8 V
1. Ignition OFF, disconnect the harness connector X1 at the K20 Engine Control Module.
2. Test for infinite resistance between the 5 V reference circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the 5 V reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.
• If greater than 5.2 V
1. Ignition OFF, disconnect the harness connector X1 at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the 5 V reference circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K20 Engine Control Module.
• If between 4.8-5.2 V
5. Ignition OFF, disconnect the harness connector X1 at the K20 Engine Control Module, Ignition ON.
6. Test for less than 1 V between the B19B Brake Booster Vacuum Sensor signal circuit terminal 1 and ground.
• If greater than 1 V
Repair the short to voltage on the circuit.
• If less than 1 V
7. Ignition OFF.
8. Test for infinite resistance between the B19B Brake Booster Vacuum Sensor signal circuit terminal 1 and ground.
• If less than infinite resistance
Repair the short to ground on the circuit.
• If infinite resistance
9. Test for less than 2 ohms between the B19B Brake Booster Vacuum Sensor signal circuit terminal 1 and the K20 Engine Control Module X1 signal circuit terminal 21.
• If 2 ohms or greater
Repair the open/high resistance in the circuit.
• If less than 2 ohms
10. Replace the B19B Brake Booster Vacuum Sensor.
11. Verify the DTC does not set while operating the vehicle under Conditions for Running the DTC.
• If the DTC sets
Replace the K20 Engine Control Module.
• If the DTC does not set
12. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Power Brake Booster Vacuum Sensor Replacement Service and Repair
* Control Module References Control Module References for Engine Control Module replacement, programming and setup.