GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2004 🢒 Epica 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C0043

Circuit Description

The pump motor is contained within the brake pressure modulator valve (BPMV). The pump motor ground is supplied though terminal D of the electronic brake control module (EBCM).

Conditions for Setting the DTC

DTC C0043 can only be set with the key in the ON position, pump motor is commanded OFF just after a run command, and the EBCM detected a seized or slowly moving pump motor.

Action Taken When the DTC Sets
    • The solenoid relay opens, removing power from the pump motor and solenoids.
    • DTC C0043 is stored.
    • The antilock brake system (ABS) is disabled and the ABS warning lamp illuminates.

Conditions for Clearing the DTC
    • If the conditions that set DTC C0043 are 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 of DTC C0043:

    • Poor terminal contact at terminal D
    • Terminal D ground circuit high resistance
    • Terminal D ground circuit open
    • BPMV pump motor malfunction
    • 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. Turn the ignition switch OFF.
  2. Disconnect the negative battery cable.
  3. Disconnect the electronic brake control module (EBCM) harness from the EBCM.
  4. Connect an ohmmeter to the negative battery cable and terminal D of the EBCM harness.

Does the resistance measure less than the specified value?

2 ohms

Go to Step 4

Go to Step 3

3

Find and repair the source of high resistance between the EBCM ground circuit and chassis ground.

Did you find and correct the condition?

--

System OK

--

4
  1. Follow the negative battery cable to the engine block and/or chassis ground connection and inspect for a good clean and tight connection.
  2. From terminal D of the EBCM harness follow the wire and find the location where the circuit grounds to the chassis. Inspect for a good clean and tight connection.

Were both connections clean and tight?

2 ohms

Go to Step 6

Go to Step 5

5

Repair the poor ground connection.

Did you complete the repair?

--

System OK

--

6
  1. Verify the EBCM harness is still disconnected.
  2. Remove the EBCM from the brake pressure modulator valve (BPMV).
  3. Inspect the EBCM to BPMV connector for conditions such as damage, corrosion, poor terminal contact, or the presence of brake fluid.

Were the terminals and connector OK, and the cavity free of brake fluid, damage, and corrosion?

--

Go to Step 8

Go to Step 7

7
  1. If damage and/or corrosion are present, replace the EBCM and/or the BPMV as necessary.
  2. If the brake fluid is present, replace both the EBCM and the BPMV.

Did you complete the replacement?

--

System OK

--

8

Connect an ohmmeter to terminal 1 and terminal 2 of the BPMV.

Was the pump motor resistance reading within the specified range?

2 ohms

Go to Step 10

Go to Step 9

9

Replace the BPMV. Refer to Brake Pressure Modulator Valve Assembly Replacement .

Did you complete the replacement?

--

System OK

--

10

Replace the EBCM.

Did you complete the replacement?

--

System OK

--