P050F

DTC P050F

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 Descriptor
DTC P050F
- Brake Assist Vacuum To Low

Circuit/System Description

The brake booster pressure sensor measures the negative air pressure or vacuum reserve in the brake booster assembly. During engine running conditions, the brake booster pressure sensor signal circuit voltage varies, depending on the vacuum reserve internal to the brake booster. If the brake booster vacuum is to low, a command to turn the engine on will be given.

Conditions for Running the DTC

Condition 1
* DTC P0556 is not set.
* The vehicle is in an AutoStop.
* Brake pressure change is less than 30 kPa (4.4 psi).

Condition 2
* DTC P0556 is not set.
* The vehicle is accelerating with the drivers foot off the brake pedal.
* Engine vacuum is less than 20 kPa.
* MAF sensor greater than 6 g/s.
* Difference in brake booster pressure and engine pressure must be at least 10 kPa (1.5 psi).
* Change in brake pressure is less than 30 kPa (4.4 psi).
* Master cylinder brake pressure is less than 200 kPa (29 psi).

Conditions for Setting the DTC

Condition 1

A vacuum leak of 0.9 kPa (.13 psi) per second is detected in the brake assist system during an Autostop.

Condition 2

A vacuum leak of 0.65 kPa (.1 psi) per second is present in the brake assist system during acceleration.

Action Taken When the DTC Sets

DTC P050F is a Type B DTC.

Conditions for Clearing the DTC

DTC P050F is a Type B DTC.

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)

Circuit/System Verification

Verify that DTC P0556, P0557, or P0558 is not set.

If the DTC is set, refer to DTC P0556, P0557, or P0558 (P0556).
If the DTC is not set, refer to Brake Assist System Diagnosis (Component Tests and General Diagnostics).