Circuit Description
The electronic brake control module (EBCM) monitors the voltage level available for system operation. A low voltage condition prevents the system from operating properly.
DTC Descriptor
This diagnostic procedure supports the following DTC
DTC C0899 Device Voltage Low
Conditions for Running the DTC
The system relay is commanded ON.
If equipped, the following actions will occur
- The EBCM disables vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
- The driver information center (DIC) displays the Service Stability System message.
Conditions for Setting the DTC
One of the following conditions exists for 0.72 seconds
- During initialization or when the system is inactive, the system voltage is less than 10.5 volts.
- During the system operation, the system voltage is less than 9 volts.
Action Taken When the DTC Sets
If equipped, the following actions will occur
- The EBCM disables the ABS.
- Dynamic rear proportioning (DRP) is degraded when the code is current.
- The EBCM disables the traction control system (TCS).
- The EBCM disables the VSES.
- The ABS indicator turns ON.
- The DIC displays the Service Stability System message.
- The DIC displays the Service Traction System message.
Conditions for Clearing the DTC
- The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
- The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
- Test the charging system. Refer to «Diagnostic System Check - Vehicle»(ref-241670-S16610990062006081100000) in Vehicle DTC Information.
- Possible causes of this DTC are the following conditions: A charging system malfunction An excessive battery draw A weak battery A faulty system ground
Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 2: Use the scan tool in order to inspect the voltage to the EBCM.
- 5: This step verifies that the condition is still present.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: ABS Schematics Connector End View Reference: ABS Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | |
| 2 | Install a scan tool. Start the engine. With a scan tool, observe the Switched Battery Voltage Signal parameter in the ABS data list. Does the scan tool indicate the voltage is greater than the specified value? | 10.5 V | Go to Diagnostic Aids | Go to Step 3 |
| 3 | With a scan tool, observe the Ignition Voltage Signal parameter in the ABS data list. Does the scan tool indicate the voltage is greater than the specified value? | 10.5 V | Go to Step 4 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 4 | Test the ground circuits of the electronic brake control module (EBCM) including the EBCM ground for 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 7 | Go to Step 5 | |
| 5 | Connect the EBCM harness connector. Turn ON the ignition, with the engine OFF. Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text. Does the DTC reset? | Go to Step 6 | Go to Diagnostic Aids | |
| 6 | Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming. Did you complete the repair? | Go to Step 7 | ||
| 7 | Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text. Does the DTC reset? | Go to Step 2 | System OK | |
DTC C0899
The electronic brake control module (EBCM) monitors the voltage level available for system operation. If the voltage level is too high, damage may result to the system. When the EBCM detects a high voltage condition, the EBCM disables the ABS system.
This diagnostic procedure supports the following DTC
DTC C0900 Device Voltage High
The vehicle speed is greater than 8 km/h (5 mph).
The system voltage is greater than 17 volts.
If equipped, the following actions will occur
- The EBCM disables the ABS.
- Dynamic rear proportioning (DRP) is degraded when the code is current.
- The EBCM disables the traction control system (TCS).
- The EBCM disables vehicle stability enhancement system (VSES).
- The ABS indicator turns ON.
- The driver information center (DIC) displays the Service Stability System message.
- The DIC displays the Service Traction System message.
- The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
- The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
A possible cause of this DTC is overcharging.
The numbers below refer to the step numbers on the diagnostic table.
- 2: Use the scan tool in order to inspect the voltage to the EBCM.
- 3: Use the scan tool in order to inspect the voltage to the body control module (BCM). A high voltage value in multiple modules indicates a concern in the charging system.
- 4: This step verifies that the condition is still present.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: ABS Schematics Connector End View Reference: ABS Connector End Views | ||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | |
| 2 | Turn OFF all of the accessories. Install a scan tool. Start the engine Run the engine at approximately 2,000 RPM. With a scan tool, observe the Switched System Battery Voltage parameter in the ABS data list. Does the scan tool indicate that the voltage is greater than the specified value? | 17 V | Go to Step 3 | Go to Diagnostic Aids |
| 3 | With a scan tool, observe the Battery Volts parameter in Body Control Module (BCM) data list. Does the scan tool indicate the voltage is greater than the specified value? | 17 V | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | Go to Step 4 |
| 4 | Use the scan tool in order to clear the DTCs. Operate the vehicle within the conditions for Running the DTC, as specified in the supporting test. Does the DTC reset? | Go to Step 5 | Go to Diagnostic Aids | |
| 5 | Replace the electronic brake control module (EBCM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming. Did you complete the repair? | Go to Step 6 | ||
| 6 | Use the scan tool in order to clear the DTCs. Operate the vehicle within the conditions for Running the DTC, as specified in the supporting test. Does the DTC reset? | Go to Step 2 | System OK | |
DTC C0900
The electronic brake control module (EBCM) uses the input from the brake fluid pressure sensor 2 to enhance Antilock Brake System (ABS) braking and vehicle stability if equipped.
This diagnostic procedure supports the following DTC
DTC C1101 Base Brake System Pressure Sensor 2 Range
- The ignition is ON for 1 second and greater than 8 volts.
- The 5-volt reference to the secondary brake pressure sensor is in range.
- The secondary brake fluid pressure sensor signal is greater than 4.9 volts.
- The secondary brake fluid pressure sensor signal is less than 0.15 volt.
If equipped, the following actions will occur
- The EBCM disables the vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
- The EBCM disables the Traction Control System (TCS) for the duration of the ignition cycle.
- The Traction Control Off indicator turns ON.
- The driver information center (DIC) displays the Service Stability System and Service Traction System message.
- The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
- The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
The brake pressure sensors are internal to the EBCM assembly and cannot be diagnosed or replaced separately. If equipped, the secondary brake pressure sensor 5-volt reference circuit and low reference circuit is shared with other components in the vehicle stability system. DTCs can set for other components that share circuits with the secondary brake pressure sensor.
The number below refers to the step number on the diagnostic table.
- 2: The EBCM supplies a 5-volt reference to several sensors. DTC C0870 is set if the 5-volt reference voltage is out of range.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: ABS Schematics Connector End View Reference: ABS Connector End Views | |||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 4 | Go to Diagnostic System Check - Vehicle |
| 2 | Is DTC C0870 set also? | Go to DTC C0870 | Go to Step 3 |
| 3 | Replace the electronic brake control module (EBCM). Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | Go to Step 4 | |
| 4 | Use the scan tool in order to clear the DTCs. Operate the vehicle within normal driving conditions. Does the DTC reset? | Go to Step 1 | System OK |
DTC C1101
Symptoms - Antilock Brake System
| IMPORTANT | The following steps must be completed before using the symptom tables. |
- Perform the «Diagnostic System Check - Vehicle»(ref-241670-S16610990062006081100000) in Vehicle DTC Information, before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data link.
- Review the system operation in order to familiarize yourself with the system functions. Refer to «ABS Description and Operation»(ref-241722-S24878921472006081100000) .