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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 936 (Antilock Brake System And Traction Control System) >> Diagnostic Information and Procedures >> DTC C0287, P1644, or P1689: Delivered Torque Circuit >> Test Description

Test Description

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

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

  1. 3:  This step tests for voltage supplied to the PCM from the EBCM.
  2. 9:  The PCM may be damaged if the delivered torque signal circuit is shorted to voltage.
DTC C0287, P1644, or P1689

Step Action Values Yes No
Schematic Reference:  ABS Schematics  
Connector End View Reference: ABS Connector End Views   or  Powertrain Control Module (PCM) Connector End Views  in Engine Controls - 4.8L, 5.3L and 6.0L 
1 Did you perform the ABS Diagnostic System Check? - Go to Step 2  Go to Diagnostic System Check - ABS 
2
  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 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 within the specified range?		 4.75-5.25 V Go to Step 5  Go to Step 4 
4 Test the delivered torque signal circuit for an open, a short to voltage 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 12  Go to Step 7 
5
  1. Turn OFF the ignition.
  2. Reconnect the PCM harness connector.
  3. Start the engine.
  4. Select the Traction Assist Data Display on the scan tool.
  5. Observe the Delivered Torque parameter on the scan tool.
Is the duty cycle of the delivered torque signal is within the specified range?		 25-95% Go to Step 6  Go to Step 9 
6
  1. Turn OFF the ignition.
  2. Install a J 39700  See 100-pin breakout box using a J 39700-325  breakout box adaptor. See Special Tools . 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 of the delivered torque signal.
Does the frequency of the delivered torque signal measure within the specified range?		 121-134 Hz Go to Step 7  Go to Step 9 
7
  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 12  Go to Step 8 
8
IMPORTANT: Following EBCM replacement, 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 12  -
9 
  1. Turn ON the ignition.
  2. 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 12  Go to Step 10 
10 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 12  Go to Step 11 
11
IMPORTANT: Perform the setup procedure for the PCM.
Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L.Did you complete the replacement?		 - Go to Step 12  -
12
  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
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