Contents Wiring diagrams Section: Anti-Lock/traction Control All sections

C0461 Chevrolet Uplander I

The difference in the phase angle between Phase A and Phase B is greater than 16 degrees continuously for 0.25 second.

Action Taken When the DTC Sets

If equipped, the following actions will occur

  1. The EBCM disables vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
  2. The driver information center (DIC) displays the Service Stability System message.

Conditions for Clearing the DTC

  1. A current DTC will clear when the malfunction is no longer present.
  2. A history DTC will clear after 100 consecutive malfunction free ignition cycles or when the scan tool Clear DTCs function is used.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to Testing for Electrical Intermittents , Testing for Intermittent Conditions and Poor Connections , Wiring Repairs and Connector Repairs in Wiring Systems.

Test Description

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

  1. 3: This step test the circuitry in the high voltage range.
  2. 4: This step test the circuitry in the low voltage range.
  3. 5: This step tests the low reference circuit of the steering wheel position sensor.
StepActionValuesYesNo
Schematic Reference: Body Control System Schematics in Computer/Integrating Systems Connector End View Reference: Computer/Integrating Systems Connector End Views in Computer/Integrating Systems
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Use the scan tool to clear the DTC. Start the engine. With the engine running, turn the steering wheel back and forth from lock to lock. Does the DTC reset?Go to Step 3Go to Diagnostic Aids
3Turn OFF the ignition. Disconnect the steering wheel position sensor harness connector. Turn ON the ignition. Select the VSES Data List on the scan tool. Observe the Analog SWPS Signal parameter on the scan tool. Does the scan tool indicate that the Steering Wheel Position Sensor Data parameter is less than specified value?0.2 VGo to Step 4Go to Step 9
4Connect a 3-amp fused jumper wire between the steering wheel position 5-volt reference circuit and the analog steering signal circuit. Observe the Analog SWPS Signal parameter on the scan tool. Does the scan tool indicate that the steering wheel position sensor data parameter is greater than specified value?4.8 VGo to Step 5Go to Step 6
5Use a DMM to measure the voltage between the steering wheel position 5-volt reference circuit and the steering wheel position low reference circuit. Does the voltage measure greater than the specified value?4.8 VGo to Step 10Go to Step 8
6Test the 5-volt reference circuit of the steering wheel position sensor for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 7
7Test the signal circuit of the steering wheel position sensor for an open or a short to ground. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 11
8Test the low reference circuit of the steering wheel position sensor for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 11
9Test the signal circuit of the steering wheel position sensor for a short to voltage. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 13
10Inspect for poor connections at the harness connector of the steering wheel position sensor. 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 14Go to Step 12
11Inspect for poor connections at the harness connector of the electronic brake control module (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 14Go to Step 13
12Replace the steering wheel position sensor. Refer to Steering Wheel Position Sensor or Steering Shaft Lower Bearing Replacement in Steering Wheel and Column. Did you complete the replacement?Go to Step 14
13Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming. Did you complete the replacement?Go to Step 14
14Use the scan tool to clear all DTCs from all modules. Operate the vehicle within the conditions for running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 2System OK

DTC C0460 or C0461

Circuit Description

The electronic brake control module (EBCM) performs several self-tests for internal problems which may affect proper operation.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC C0550 Electronic Control Unit (ECU) Performance

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The EBCM detects an internal malfunction.

One or more of the following actions may occur

  1. The EBCM disables the ABS/dynamic rear proportioning (DRP)/TCS/vehicle stability enhancement system (VSES).
  2. The ABS indicator turns ON.
  3. The brake warning indicator turns ON.
  4. The message center displays the service stability system message.
  5. The traction off indicator turns ON.

Certain conditions that may cause this DTC to set cannot be cleared. Other conditions that may cause this DTC to set may be cleared, at least temporarily, by using the scan tool Clear DTCs function.

Replace the EBCM if this DTC continues to set intermittently.

StepActionYesNo
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Use a scan tool in order to clear the DTCs. Can the DTC be cleared?Go to Step 3Go to Step 4
3Test drive the vehicle. Refer to Diagnostic Test Drive . Does the DTC reset?Go to Step 4Go to Diagnostic Aids
4Replace the electronic brake control module (EBCM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming. Did you complete the replacement?Go to Step 5
5Use the scan tool to clear the DTCs. Turn OFF the ignition for 5 seconds. Turn ON the ignition. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 3System OK

DTC C0550

The electronic brake control module (EBCM) disables the traction control when other electronic control modules set DTCs for components that effect the operation of the traction control system.

This diagnostic procedure supports the following DTC

DTC C0561 System Disabled Information Stored

  1. The ignition is ON.
  2. Ignition voltage is greater than 8 volts.

The PCM or BCM diagnoses a condition preventing the engine control portion of the traction control function and sends a serial data message to the EBCM indicating that torque reduction is not allowed. The PCM or BCM will typically set a DTC and the EBCM will set this DTC.

Engine torque reduction traction control is disabled. The brake intervention traction remains operational.

  1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
  2. The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

This DTC is for information only. As an aid to the technician, this DTC indicates that there are no problems in the ABS/TCS system.

StepActionYesNo
Schematic Reference: ABS Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

DTC C0561

The electronic brake control module (EBCM) supplies the 5-volt reference to the following sensors

  1. The steering wheel position sensor (SWPS)
  2. The yaw rate and lateral acceleration sensor
  3. The master cylinder brake pressure sensors internal to the EBCM

This diagnostic procedure supports the following DTC

DTC C0870 Device Voltage Reference Output (Single or 1) Circuit

Ignition voltage is greater than 8 volts.

One or more of the following conditions are met

  1. When the EBCM commands the 5-volt reference ON, the output is less than 4.9 volts or greater than 5.1 volts.
  2. When the EBCM commands the 5-volt reference OFF, the output is greater than 0.5 volt.

If equipped, the following actions will occur

  1. The EBCM disables the vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
  2. The driver information center (DIC) displays the Service Stability System message.
  3. The EBCM disables the traction control system (TCS) for the duration of the ignition cycle.
  4. The DIC displays the Service Traction Control System message.
  1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
  2. The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Multiple VSES DTCs can set if the 5-volt reference is shorted to ground or power.

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

  1. 2: This step tests for a short to ground or voltage on the 5-volt reference circuit.
  2. 3: This step tests for an internal short to ground in the yaw rate and lateral accelerometer sensor.
  3. 4: This step tests for an internal short to ground in the SWPS.
StepActionYesNo
Schematic Reference: ABS Schematics Connector End View Reference: ABS Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Check for a short to ground or voltage on the 5-volt reference circuit of the following sensors: The yaw rate and lateral acceleration sensor The steering wheel position sensor (SWPS) Did you find and correct the condition?Go to Step 8Go to Step 3
3Clear the DTCs with the scan tool. Turn OFF the ignition. Disconnect the yaw rate and lateral acceleration sensor. Turn ON the ignition. Does DTC C0870 set?Go to Step 4Go to Step 5
4Reconnect the yaw rate and lateral acceleration sensor. Clear the DTCs with the scan tool. Turn OFF the ignition. Disconnect the SWPS. Turn ON the ignition. Does DTC C0870 set?Go to Step 7Go to Step 6
5Replace the yaw rate and lateral acceleration sensor. Refer to Yaw Rate Sensor/Lateral Accelerometer Replacement . Did you complete the replacement?Go to Step 8
6Replace the SWPS. Refer to Steering Wheel Position Sensor or Steering Shaft Lower Bearing Replacement . Did you complete the replacement?Go to Step 8
7Replace the electronic brake control module (EBCM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming. Did you complete the replacement?Go to Step 8
8Clear the DTCs using the scan tool. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?Go to Step 2System OK

DTC C0870