GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Allure 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C0896

Circuit Description

The electronic brake control module (EBCM) is required to operate within a specified range of voltage to function properly. During ABS and traction control system (TCS) operation, there are current requirements that will cause the voltage to drop. Because of this, voltage is monitored out of ABS/TCS control to indicate a good charging system condition, and also during ABS/TCS control when voltage may drop significantly. The engine control module (ECM) also monitors for high voltage conditions which could damage the EBCM.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0896 Device Voltage Range/Performance

Conditions for Running the DTC
    • The ignition is ON.
    • The vehicle speed is greater than 5 km/h (3 mph).

Conditions for Setting the DTC
    • The EBCM operating voltage at terminal 8 falls below 9.4 volts out of ABS/TCS control, or 8.8 volts during ABS/TCS control.
    • The EBCM operating voltage at terminal 8 rises above 17.4 volts.
    • The low voltage or the high voltage is detected for more than 500 milliseconds with the vehicle speed above 6 km/h (3.6 mph).

Action Taken When the DTC Sets

If equipped, the following actions occur:

    • The EBCM disables the ABS/TCS/vehicle stability enhancement system (VSES) and for the duration of the ignition cycle.
    • A malfunction DTC will set.
    • The ABS indicator turns ON.
    • The Stability Off indicator turns ON.

Conditions for Clearing the DTC
    • The condition for the DTC is no longer present, the scan tool Clear DTCs function is used.
    • 100 ignition cycles have passed with no DTCs detected.

Diagnostic Aids
    • It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
    • Thoroughly inspect any circuitry that may be causing the complaint for the following conditions:
       - Backed out terminals
       - Improper mating
       - Broken locks
       - Improperly formed or damaged terminals
       - Poor terminal-to-wiring connections
       - Physical damage to the wiring harness
    • The following conditions may cause an intermittent malfunction:
       - A poor connection
       - Rubbed-through wire insulation
       - A broken wire inside the insulation
    • If an intermittent malfunction exists, refer to General Electrical Diagnosis in Wiring Systems for further diagnosis.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step checks if the voltage is above the maximum of the range.

    2.

  2. This step checks if the voltage is below the minimum of the range.

    3.

  3. This step checks for the integrity of the ground circuit.

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System 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

  1. Turn all the accessories OFF.
  2. Install a scan tool.
  3. Start the engine.
  4. Use the scan tool to monitor the battery voltage while running the engine at approximately 2,000 RPM.

Is the monitored battery voltage within the specified range?

0-17.4 V

Go to Step 4

Go to Step 3

3

Use a DMM to measure the voltage between the battery positive terminal and ground.

Is the voltage within the specified range?

0-17.4 V

Go to Step  5

Go to Charging System Test in Engine Electrical

4

Continue to monitor the battery voltage with the scan tool while running the engine at approximately 2,000 RPM.

Is the monitored battery voltage within the specified range?

0-9.4 V

Go to Step 6

Go to Step 5

5
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the scan tool if still connected.
  3. Test drive the vehicle above 5 km/h (3 mph).

Did DTC C0896 reset?

--

Go to Step 12

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

6

  1. Disconnect the electronic brake control module (EBCM) connector from the EBCM.
  2. Install the J 39700 Universal Pinout Box with the J 39700-530 Cable Adapter to the EBCM harness only.
  3. Use a DMM to measure the resistance between the J 39700 terminal 15 and a good ground.

Is the resistance within the specified range?

0-5 ohms

Go to Step 8

Go to Step 7

7

Repair open or high resistance in EBCM ground circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 13

--

8
  1. Turn the ignition switch to the ON position with the engine OFF.
  2. Use a DMM to measure the voltage between the J 39700 terminal 8 and 15.

Is the voltage above the specified value?

9.4 V

Go to Step 11

Go to Step 9

9
  1. Remove the 10A ABS fuse from the underhood accessory wiring junction block.
  2. Use a DMM to measure the resistance between the underhood accessory wiring junction block connector C1 terminal E4 and the J 39700 terminal 8.

Is the resistance within the specified range?

0-5 ohms

Go to Charging System Test in Engine Electrical

Go to Step 10

10

Repair high resistance or open in the IGN circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 13

--

11
  1. Turn the ignition switch to the OFF position.
  2. Reconnect the EBCM connector.
  3. Disconnect the scan tool if the scan tool is still connected.
  4. Test drive the vehicle above 5 km/h (3 mph).

Did DTC C0896 reset?

--

Go to Step 12

Go to Step 13

12

Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Is the repair complete?

--

Go to Step 13

--

13
  1. Use the scan tool in order to clear the DTCs.
  2. 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