GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 Epica 🢒 Body Systems 🢒 Fixed and Moveable Windows 🢒 DTC C2402

Circuit Description

The pump motor is contained within the brake pressure modulator valve (BPMV). The pump motor ground is supplied though terminal 24 of the electronic brake control module (EBCM).

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C2402 Pump Motor Circuit

Conditions for Running the DTC
    • Ignition is in the ON position.
    • Pump motor is OFF just after a run command

Conditions for Setting the DTC

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 C2402 is stored.
    • ABS disabled, ABS warning lamp illuminates.

Conditions for Clearing the DTC
    • If the conditions that set DTC C2402 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 for DTC C2402:

    • Poor terminal contact at terminal 24
    • Terminal 24 ground circuit high resistance
    • Terminal 24 ground circuit open
    • BPMV pump motor malfunction
    • EBCM malfunction

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Component Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn the ignition switch OFF.
  2. Disconnect the negative battery cable.
  3. Disconnect the electronic brake control module (EBCM) harness connector from the EBCM.
  4. Connect an ohmmeter to the negative battery cable and terminal 24 of the EBCM harness.

Was the resistance reading less than the specified value?

2 Ω

Go to Step 4

Go to Step 3

3

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

Did you find and correct the condition?

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Go to Step 11

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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 24 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?

--

Go to Step 6

Go to Step 5

5

Repair the poor ground connection.

Did you find and correct the condition?

--

System OK

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6
  1. 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. Refer to Brake Pressure Modulator Valve Assembly Replacement .
  2. If the brake fluid is present, replace both the EBCM and the BPMV. Refer to Brake Pressure Modulator Valve Assembly Replacement .

Did you complete the replacement?

--

Go to Step 11

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8

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

Was the pump motor resistance reading less than the specified value?

2 Ω

Go to Step 10

Go to Step 9

9

Replace the brake pressure modulator valve. Refer to Brake Pressure Modulator Valve Assembly Replacement .

Did you complete the replacement?

--

Go to Step 11

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10

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

Did you complete the replacement?

--

Go to Step 11

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11
  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 2

System OK