During calibration of the offset of the pressure sensor signal, the pressure sensor signal offset value must be in the range of 1-15 Bar (1-434 psi).
The pressure sensor is also monitored for sensitivity via a correlation between estimated vehicle deceleration and the pressure sensor signal. This is monitored over the course of numerous straight line non ABS braking stops.
• | The ignition is ON. |
• | The vehicle speed is greater than 40 km/h (25 mph). |
• | The sensor signal offset value is out of range for more than 1 second. |
• | The brake pedal is not applied. |
• | The ABS pump is not on. |
• | The brake pressure sensor sensitivity is outside a predetermined range. |
• | The brake pressure sensor indicates low brake fluid pressure, and the brake pedal position sensor indicates brakes applied. |
If equipped, the following actions occur:
• | The EBCM disables the ABS/TCS/VSES for the duration of the ignition cycle. |
• | A malfunction DTC will set. |
• | The ABS indicator turns ON. |
• | The Stability Off indicator turns ON. |
• | The Red BRAKE Warning indicator could turn on. |
• | The condition for the DTC is no longer present. |
• | A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present. |
• | Using a scan tool |
• | A malfunctioning pressure sensor |
• | A malfunctioning EBCM |
• | Test the brake pedal position sensor for proper operation, and adjustment. A improperly adjusted BPPS will set the DTC. |
The numbers below refer to the step numbers on the diagnostic table.
Tests for DTCs set in the Body Control Module BCM Lighting Systems for a malfunctioning brake pedal position sensor BPPS.
Tests for specified voltage on the brake pressure signal circuit.
Checks to see if voltage was below specified voltage.
Checks to see if voltage was above specified voltage.
Checks to see if voltage was above specified voltage of 5 volt reference.
Checks to see if 5 volt reference from EBCM is 5 volts.
Checks to see if resistance of ground circuit is less than 5 ohms.
Tests for short to voltage in the 5 volt reference circuit.
Tests for a short to ground, a high resistance or an open in the 5 volt reference circuit.
Tests for a short to voltage in the brake pressure sensor signal circuit.
Tests for a high resistance or an open in the ground circuit.
Checks to brake pressure sensor connector for poor connections.
Checks to EBCM connector for poor connections.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics Connector End View Reference: Antilock Brake System Connector End Views | ||||
1 | Did you perform the ABS Diagnostic System Check? | -- | Go to Step 2 | |
After performing the ABS Diagnostic System Check, retrieve DTCs set for the brake pedal position sensor BPPS in Lighting Systems. Did the BPPS set DTCs? | -- | Go to Diagnostic Trouble Code (DTC) List in Lighting Systems | Go to Step 3 | |
Is the voltage within the specified value? | 0.25-4.75 V | Go to Diagnostic Aids | Go to Step 4 | |
Is the voltage less than the specified value? | 4.75 V | Go to Step 5 | Go to Step 11 | |
Is the voltage greater than the specified value? | 0.25 V | Go to Step 6 | Go to Step 9 | |
Does the voltage measure less than the specified value? | 5 V | Go to Step 7 | Go to Step 8 | |
Does the resistance measure less than the specified value? | 5 ohms | Go to Step 13 | Go to Step 12 | |
Test the 5 volt reference circuit of the brake pressure sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 | |
Test the 5 volt reference circuit of the brake pressure sensor for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 10 | |
Test the signal circuit of the brake pressure sensor for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 | |
Test the signal circuit of the brake pressure sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 | |
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 | |
Inspect for poor connections at the harness connector of the brake pressure sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 15 | |
Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 16 | |
15 | Replace the brake pressure sensor Brake Fluid Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- |
16 | Important Before replacing the EBCM, inspect the brake pedal position sensor for proper adjustment, Refer to Brake Pedal Position Sensor Calibration Description and Operation in Lighting System. Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- |
17 |
Does the DTC reset? | -- | Go to Step 2 | System OK |