GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Spark 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC 2321

Circuit Description

Battery voltage is supplied to the antilock brake system (ABS) warning lamp with the ignition switch ON. The warning lamp can be activated only by the electronic brake control module (EBCM) internally supplying ground to terminal 20 or by the shorting bar in the EBCM connector when it is disconnected from the module.

Conditions for Running the DTC

When the battery voltage is applied to terminal 20 of the EBCM connector with the ignition ON, this fault code happens.

Conditions for Setting the DTC

The ABS warning lamp circuit is shorted to the battery and the warning lamp is ON continuously.

Action Taken When the DTC Sets

This is a critical operational fault. The ABS is disabled and the ABS warning lamp is turned ON. The proportioning is operation.

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1
  1. Turn the ignition switch to OFF.
  2. Disconnect the EBCM harness connector.
  3. Use an insulated tool to push the shorting bar in the connector away from terminal 20 and terminal ground of the EBCM harness connector.
  4. Use a jumper to connect terminal 20 and terminal ground of the EBCM harness connector.
  5. Turn the ignition switch to ON.

Is the ABS indicator on?

--

Go to Step 11

Go to Step 2

2
  1. Turn the ignition switch to OFF.
  2. Disconnect the I/P cluster connector.
  3. Turn the ignition switch to ON.
  4. Connect a test light between terminal B6 of the I/P cluster connector and ground.

Is the test light on?

--

Go to Step 5

Go to Step 3

3
  1. Remove the fuse F1 in the I/P fuse block.
  2. Check for an open in fuse F1.

Is the fuse open?

--

Go to Step 5

Go to Step 4

4

Replace the fuse F1.

Is the repair complete?

--

System OK

--

5
  1. Turn the ignition switch to OFF.
  2. Disconnect the I/P cluster connector.
  3. Use a digital voltmeter (DVM) to measure the resistance between terminal B5 and B6 of the I/P cluster connector.

Is the resistance below the specified value?

20 ohms

Go to Step 7

Go to Step 6

6

Replace the ABS indicator bulb.

Is the repair complete?

--

System OK

--

7
  1. Disconnect the connector C206.
  2. Use a DVM to measure the resistance between terminal B5 of the I/P cluster harness connector and terminal 8 of the connector C206.

Is the resistance below the specified value?

1 ohms

Go to Step 9

Go to Step 8

8

Repair the open or high resistance between terminal B5 the I/P cluster harness connector and terminal 8 of the connector C206.

Is the repair complete?

--

System OK

--

9

Use a DVM to measure the resistance between terminal 8 of the connector C206 and terminal 20 of the EBCM harness connector.

Is the resistance below the specified value?

1 ohms

Go to Step 11

Go to Step 10

10

Repair the open or high resistance between terminal 20 of the EBCM harness connector and terminal 8 of the connector C206.

Is the repair complete?

--

System OK

--

11
  1. Remove the fuse F1 in the I/P fuse block.
  2. Disconnect the I/P cluster connector.
  3. Turn the ignition switch to ON.
  4. Use a DVM to measure the voltage between terminal 8 of the connector C206 and ground.

Is the voltage within the specified value?

0 V

Go to Step 13

Go to Step 12

12

Repair the shorted to battery voltage between terminal 8 of the connector C206 and fuse F1 output in the I/P fuse block.

Is the repair complete?

--

System OK

--

13

Use a DVM to measure the voltage between terminal 20 of the EBCM connector and ground.

Is the voltage within the specified value?

0 V

Go to Step 15

Go to Step 14

14

Repair the shorted to battery voltage between terminal 8 of the connector C206 and terminal 20 of the EBCM connector.

Is the repair complete?

--

System OK

--

15

Replace the EBCM.

Is the repair complete?

--

System OK

--