Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC C1100 00: Base Brake System Pressure CircuitDTC C1100 01: Base Brake System Pressure Circuit Short to Battery
DTC C1100 02: Base Brake System Pressure Circuit Short to Ground
DTC C1100 08: Base Brake System Pressure Circuit Signal Invalid
DTC C1100 09: Base Brake System Pressure Circuit Rate of Change Above Threshold
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Brake Booster Vacuum Sensor 5-Volt Reference | C1100 02 | C1100 00, 08 | C1100 01 | C1100 08 |
Signal | C1100 00, 02 | C1100 00 | C1100 00,01 | C1100 09, 08 |
Low Reference | C1100 00 | C1100 00 | -- | C1100 09, 08 |
Circuit/System Description
The electronic brake control module (EBCM) provides a 5-volt reference to the brake booster vacuum sensor. The brake booster vacuum sensor converts the change in vacuum levels in the brake booster into a voltage signal. This signal is sent to the EBCM. The voltage signal ranges, from 0.13-3.30 volts depending on vacuum levels.
Conditions for Running the DTC
C1100 00, 01, 02
| • | Ignition ON. |
| • | 5-volt reference voltage is between 4.8-5.2 volts |
C1100 08
| • | The HCU internal pressure sensor is ok. |
| • | Vacuum pressure in the brake booster is less than -200mbar. |
C1100 09
| • | 5-volt reference voltage is between 4.8-5.2 volts |
| • | Brake pedal is not applied |
| • | Speed is above 6 mph (10kph) |
Conditions for Setting the DTC
C1100 00, 01, 02
The EBCM detects a short to voltage, short to ground or open/high resistance.
C1100 08, 09
| • | After the brake pedal has been applied 3 times during one ignition cycle. |
| • | The EBCM detects the vacuum sensor reading is not plausible. |
Action Taken When the DTC Sets
C1100 00, 01, 02
| • | The EBCM disables the vehicle stability enhancement system, the optimized hydraulic boost and traction control |
| • | A warning message/indicator is illuminated |
C1100 08, 09
A warning message is illuminated
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present. |
| • | The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the brake booster vacuum sensor.
- Ignition OFF, test for less than 5 ohms between the low reference circuit terminal 2 and ground.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and the signal circuit terminal 1.
- Ignition OFF, disconnect the harness connector at the EBCM.
- Ignition OFF, test for infinite resistance between the signal circuit terminal 41 and ground.
- If all circuits test normal, test or replace the power brake booster vacuum sensor.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the EBCM. |
| ⇒ | 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 EBCM. |
| ⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM. |
| ⇒ | If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the EBCM. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the EBCM. |
| ⇒ | If not the specified value, test the signal circuit for a short to ground. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for EBCM replacement, setup, and programming |
