GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The EBTCM is required to operate within a specified range of voltage to function properly. During ABS and 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 EBTCM also monitors for high voltage conditions which could damage the EBTCM.

Conditions for Setting the DTC

    • The EBTCM operating voltage at terminal 8 falls below 9.4 volts out of ABS/TCS control, or 8.8 volts during ABS/TCS control.
    • The EBTCM 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

    • A malfunction DTC is stored.
    • The ABS/TCS indicator lamps are turned on.
    • The ABS/TCS is disabled.

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 DTC(s) 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 number(s) below refer to the step number(s) on the diagnostic table.

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

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

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

Step

Action

Value(s)

Yes

No

SCHEMATIC REFERENCE: ABS Schematics

Power, Ground, Serial Data and EBCM


Object Number: 588293  Size: FS
Cell 10
Cell 10: Underhood Accessory Wiring Junction Block
Antilock Brake System Component Views
ABS Description
Cell 44: Instrument Cluster Indicators, MSVA and Stop Lamp Switch
Handling ESD Sensitive Parts Notice
Cell 14: LH I/P Ground G205
Cell 11: TCC, ELEK IGN and A/C CLU/ABS IGN Fuses
Cell 50
Handling ESD Sensitive Parts Notice

1

Was a Diagnostic System Check performed?

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Go to Step 2

Go to Diagnostic System Check - ABS

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 2000 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 J 39200 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 2000 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 6 km/h (3.5 mph).

Did DTC C0896 reset?

--

Go to Step 12

Go to Diagnostic System Check - ABS

6

  1. Disconnect the EBTCM connector from the EBTCM.
  2. Install the J 39700 Universal Pinout Box with the J 39700-530 Cable Adapter to the EBTCM harness only.
  3. Use a J 39200 DMM to measure the resistance between the J 39700 terminal 15 and a good ground.

Is the resistance within the specified range?

0-5ohms

Go to Step 8

Go to Step 7

7

Repair open or high resistance in CKT 251. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

8

  1. Turn the ignition switch to the RUN position with the engine off.
  2. Use a J 39200 DMM to measure the voltage between the J 39700 terminal 8 and 15.

Is the voltage within the specified range?

Above 9.4 Volts

Go to Step 11

Go to Step 9

9

  1. Disconnect the Underhood Accessory Wiring Junction Block connector C 1.
  2. Use a J 39200 DMM to measure the resistance between the Underhood Accessory Wiring Junction Block connector C 1 terminal E 8 and the J 39700 terminal 8.

Is the resistance within the specified range?

0-5ohms

Go to Charging System Test in Engine Electrical

Go to Step 10

10

Repair high resistance in CKT 1239. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

11

  1. Turn the ignition switch to the OFF position.
  2. Reconnect the EBTCM connector.
  3. Disconnect the scan tool if the scan tool is still connected.
  4. Test drive the vehicle above 6 km/h (3.5 mph).

Did DTC C0896 reset?

--

Go to Step 12

Go to Diagnostic System Check - ABS

12

Replace the EBTCM. Refer to Electronic Brake and Traction Control Module Replacement .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

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