GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This circuit is used to monitor the voltage level available to the electronic brake control module (EBCM). If the voltage rises above a certain level, damage to the system may occur.

Conditions for Setting the DTC

DTC C0037 can only be set if the vehicle speed is greater than 8 km/h (5 mph), if the voltage supplied to terminals A and/or B is greater than 17 volts for 1 second.

Action Taken When the DTC Sets

    • The solenoid relay opens, removing voltage from the solenoids and pump motor.
    • DTC C0037 is stored.
    • The antilock brake system (ABS) is disabled, ABS warning lamp turns ON.

Conditions for Clearing the DTC

    • If the conditions that set DTC C0037 is no longer present, the DTC may be cleared by using the proper scan tool.
    • The DTC that has not occurred in 100 drive cycles will be cleared from history data.

Diagnostic Aids

Typical causes for DTC C0037 to set:

    • Charging system malfunction
    • Poor connection
    • EBCM malfunction

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check-ABS?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Connect a voltmeter to the positive and negative terminals of the battery.
  2. Turn OFF all accessories.
  3. Start the engine.
  4. Monitor the voltage on the meter with the engine running at 2000 RPM for several seconds.

Does the voltage measure less than the specified value?

17 V

Go to Step 4

Go to Step 3

3

  1. Repair the starter and charging system.
  2. Replace the starter and charging system as needed.

Did you find and correct the condition?

--

System OK

--

4

  1. Connect a scan tool and select ABS data list.
  2. Monitor battery voltage on the ABS data list while running the engine at 2000 RPM for several seconds.

Does the voltage measure less than the specified value?

17 V

Go to Step 6

Go to Step 5

5

Replace the EBCM.

Did you complete the replacement?

--

System OK

--

6

The condition is intermittent. Refer to Diagnostic Aids.

Did you find and correct the condition?

--

System OK

--