GM Service Manual Online
For 1990-2009 cars only

DTC C0244 W/O JL4

Circuit Description

The ABS relay supplies battery voltage to 6 valve solenoids. The electronic brake control module (EBCM) microprocessor applies the grounds needed to activate each solenoid. The low side of each solenoid coil has a feedback circuit to the EBCM microprocessor. When a solenoid is commanded OFF, the feedback voltage is high. When a solenoid is commanded ON, the feedback voltage is low.

Conditions for Running the DTC

    • The ignition is ON.
    • The vehicle speed is greater than 6 km/h (4 mph).

Conditions for Setting the DTC

The EBCM detects an internal malfunction.

Action Taken When the DTC Sets

    • The EBCM disables the ABS.
    • The ABS indicator turns ON.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

An intermittent open/shorted solenoid DTC can be set by several different internal EBCM problems. Replace the EBCM if an open/shorted solenoid DTC continues to set intermittently.

Step

Action

Yes

No

1

Did you perform the ABS Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Use a 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 set?

Go to Step 3

Go to Diagnostic Aids

3

Important: Following EBCM replacement, use the scan tool to perform the Tire Size Calibration procedure and the Trim Level Calibration procedure, if applicable.

Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Did you complete the replacement?

Go to Step 4

--

4

  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 3

System OK

DTC C0244 W/JL4

Circuit Description

The EBCM supplies approximately 12 volts through an internal resistor to the powertrain control module (PCM) on the delivered torque signal circuit. The PCM toggles this voltage to ground in order to create the delivered torque signal at the EBCM. A signal with a frequency of 128 Hz +/- 5 percent and a duty cycle of 25-95 percent is a valid delivered torque signal. The percentage of duty cycle is proportionate to the percentage of delivered engine torque.

Conditions for Running the DTC

    • The ignition is ON.
    • The engine is running at a speed greater than 450 RPM for 1 second.

Conditions for Setting the DTC

The EBCM receives an invalid delivered torque signal for 300 milliseconds.

Action Taken When the DTC Sets

    • The EBCM disables the VSES.
    • Engine torque reduction is disabled.
    • The traction off indicator turns ON.
    • The message center displays the service stability system message.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to the following:

    •  Testing for Electrical Intermittents
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs
    •  Connector Repairs

Test Description

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

  1. This step tests for voltage supplied to the PCM from the EBCM.

  2. This step tests for a shorted resistor in the EBCM or a short to voltage within the circuit, by verifying that a large voltage drop occurs in the circuit when the test lamp is placed in parallel with the DMM. The PCM may be damaged if either of these conditions is present.

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

Connector End View Reference: Powertrain Control Module Connector End Views in Engine Controls - 4.8L, 5.3L and 6.0L

1

Did you performs the ABS Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Use a scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 5 seconds.
  3. Start the engine.

Does the DTC set?

--

Go to Step 3

Go to Diagnostic Aids

3

  1. Turn OFF the ignition.
  2. Disconnect from the PCM, the harness connector containing the delivered torque signal circuit.
  3. Turn ON the ignition.
  4. Use a DMM in order to measure the voltage between the delivered torque signal circuit and a good ground.

Does the voltage measure greater than the specified value?

10 V

Go to Step 4

Go to Step 5

4

  1. With the DMM still connected to monitor the delivered torque signal circuit, connect one end of a test lamp to a good ground.
  2. Connect the other end of the test lamp to the positive lead of the DMM, while observing the DMM display.

Does the voltage measure less than the specified value?

0.15 V

Go to Step 6

Go to Step 10

5

Test the delivered torque signal circuit for an open, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 8

6

  1. Turn OFF the ignition.
  2. Reconnect the PCM harness connector.
  3. Start the engine.
  4. Select the VSES Data Display function on the scan tool.
  5. Observe the Delivered Torque parameter on the scan tool.

Does the scan tool display a duty cycle of the delivered torque signal within the specified range?

25-95%

Go to Step 7

Go to Step 11

7

  1. Turn OFF the ignition.
  2. Install a J 39700 and a J 39700-650 adapter cable. Install the equipment between the EBCM and the EBCM harness connector.
  3. Start the engine.
  4. Use a DMM in order to measure the Hz frequency between the delivered torque signal circuit and a ground circuit.

Does the Hz frequency of the delivered torque signal measure within the specified range?

121-134 Hz

Go to Step 9

Go to Step 12

8

  1. Turn OFF the ignition.
  2. Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 9

9

Important: Following EBCM replacement, perform the set-up procedure for the EBCM and perform the Yaw Rate Reference Table Reset Procedure. Use the scan tool to perform the Tire Size Calibration procedure.

Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Did you complete the replacement?

--

Go to Step 13

--

10

Test the delivered torque signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

11

Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

12

Important: Perform the setup procedure for the PCM.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L.

Did you complete the replacement?

--

Go to Step 13

--

13

  1. Use the scan tool Clear All Class 2 DTCs function to clear all of the DTCs from all modules.
  2. Turn OFF the ignition for 5 seconds.
  3. Turn ON the ignition.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 3

System OK