C1100

DTC C1100

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 C1100 00
- Vacuum Sensor Out of Range

DTC C1100 01
- Vacuum Sensor Short to Voltage

DTC C1100 06
- Vacuum Sensor Short to Ground

DTC C1100 5A
- Vacuum Sensor Not Plausible

Diagnostic Fault Information





Circuit/System Description

The brake booster vacuum sensor measures the vacuum in the brake booster assembly. The electronic brake control module (EBCM) 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 EBCM.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC

C1100 00

If the vacuum sensor 5 V reference circuit is greater than 4.9 V for more than 100 m/sec.

C1100 01

The EBCM detects a voltage greater than 4.9 V for more than 100 m/sec on the vacuum sensor 5 V reference circuit.

C1100 02

The EBCM detects a voltage less than 0.2 V for more than 100 m/sec on the vacuum sensor 5 V reference circuit.

C1100 08, C1100 09, and C1100 5A
* The vacuum sensor signal is not plausible.
* Defective wiring vacuum sensor, or microprocessor feedback may cause erratic pressure sensor fault.

Action Taken When the DTC Sets

The brake warning indicator turns ON.

Conditions for Clearing the DTC

* A current DTC clears when the diagnostic runs and passes.
* The EBCM will turn OFF the indicator in the next ignition cycle.

Reference Information
Schematic Reference

Hydraulic Brake Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

ABS Description and Operation (Description and Operation)
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)

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 10 ohm 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 EBCM.

3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground.

• If less than the specified range, test the 5 V 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 V reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM.

4. Ignition ON, test for 4.5-5.2 V between the 5 V reference circuit terminal 3 and the signal circuit terminal 1.

• 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.

5. Ignition OFF, disconnect the X1 harness connector at the EBCM.
6. Ignition OFF, test for infinite resistance between the signal circuit terminal 21 and ground.

• If not the specified value, test the signal circuit for a short to ground.

7. If all circuits test normal, test or replace the power brake booster vacuum sensor.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Control Module References (Programming and Relearning) for EBCM replacement, setup and programming