GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2005 🢒 Wave 🢒 Body 🢒 Data Link Communications 🢒 Diagnostic System Check - ABS

Circuit Description

The Diagnostic Circuit Check is organized method of identifying any problems caused by a malfunction in the ABS/DDRP system.

A service technician should begin diagnosis of any ABS/DDRP complaint with the Diagnostic Circuit Check. The Diagnostic Circuit Check directs a service technician to the next logical step when diagnosing a complaint.

Serial data is transmitted/received by the electronic brake control module (EBCM) through terminal 7. The EBCM is supplied with constant battery feed voltage through terminals 9 and 25, and switched ignition voltage through terminal 4. The EBCM ground is provided through terminal 8 and 24.

Diagnostic Aids

Use the following ordered procedure when servicing the ABS/DDRP system.

  1. Inspect the vehicle for any mechanical conditions related to the brake system.
    2. • Verify the Brake reservoir fluid level is correct.
    • Inspect master for fluid contamination.
    • Inspect the brake master/modulator for leaks.
    • Inspect brake components at all wheels.
    • Verify no brake drag exists after brake switch adjustment.
    • Verify even brake application with no pull or lead.
    • Inspect for worn/damaged brake pads.
    • Inspect for worn/damaged wheel bearings.
    • Inspect wheel speed sensor/wiring.
    • Inspect exciter rings for damage.
    • Inspect tires for tread depth/wear.
    • Road test the vehicle to verify the complaint.
  2. Perform the Diagnostic System Check and proceed to the applicable diagnostic trouble code as necessary.
  3. Clear the ABS DTCs after all of the system malfunctions have been corrected.

Step

Action

Yes

No

1
  1. Connect or install all previously disconnected or removed components if applicable.
  2. Turn the Ignition switch ON.
  3. Install the applicable scan tool into the DLC and attempt to communicate with the EBCM.

Does the scan tool communicate with the EBCM?

Go to Step 2

Go to Step 4

2

Where any DTCs stored current or history?

Go to Step 3

Go to Step 6

3
  1. Document Current DTCs.
  2. Document History DTCs.
  3. Document Enhanced History Data such as:
    4. • Number of times each DTC set
    • Number of times since each DTC first set
    • Speed when each DTC set
    • Other Enhanced Data which may assist with diagnosis
  4. Do not clear DTCs prior to fully documenting the information from the scan tool.

Were any DTCs stored?

Refer to Diagnostic Trouble Code (DTC) List

Go to Step 6

4

Does the scan tool communicate with other modules on the data line?

Refer to No Communication with Electronic Brake Control Module

Go to Step 5

5
  1. Repair the DLC harness.
  2. Replace the DLC harness as needed.

Did you complete the repair?

System OK

--

6
  1. Turn the Ignition switch OFF.
  2. Wait 10 seconds.
  3. Turn the Ignition switch ON.
  4. Observe the amber ABS lamp when the key is turned ON.

Did the ABS warning lamp and brake warning lamp turn on for 3 seconds and then turn OFF bulb test?

System OK

Refer to Symptoms - Antilock Brake System