GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The YSC relay supplies battery voltage to 4  valve solenoids (priming, charging, supply and YSC). The EBCM microprocessor applies the grounds needed in order 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 VSES.
    • 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

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