GM Service Manual Online
For 1990-2009 cars only

Object Number: 155194  Size: MF
ABS Components
Antilock Brake System Schematics
Power Distribution Schematics
Fuse Block Schematics
Power Distribution Schematics
Handling ESD Sensitive Parts Notice
Instrument Cluster: Analog Schematics
Ground Distribution Schematics
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice
Antilock Brake System Schematics

Circuit Description

This symptom table tests the state of the ABS warning indicator in order to identify either of the following conditions:

    • The ABS warning indicator could not warn the driver of a system malfunction
    • The ABS warning indicator is always off

The EBCM/EBTCM must provide a ground in order to turn the amber ABS warning indicator off because of an integral lamp driver module within the instrument panel cluster. Because of the circuitry in the integral Lamp Driver Module (LDM), only external malfunctions can be detected. As a result, the integral LDM is not diagnosable. If CKT 867 is open, the ABS warning indicator will remain on due to the loss of ground at the integral LDM input. If the control line is shorted to ground, the ABS warning indicator will remain off. The ABS warning indicator will remain off because the integral LDM input will be grounded. DTC C1211 or DTC C1311 will set if any of the following conditions exist:

    • An open in CKT 867
    • A short to ground on CKT 867
    • A short to voltage in CKT 867

Diagnostic Aids

Use the Lamp Test function of the Scan Tool in order to turn the indicator on while looking for an intermittent malfunction in the ABS warning indicator circuitry.

Thoroughly inspect any circuitry that may cause the intermittent complaint for the following conditions:

    • Rubbed-through wire insulation
    • A broken wire inside the insulation
    • Backed out terminals
    • Improper mating
    • Broken locks
    • Improperly formed or damaged terminals
    • Poor terminal-to-wiring connections
    • Physical damage to the wiring harness

Important: Zero the J 39200 test leads before making any resistance measurements.

ABS Warning Indicator Off/No DTCs Set (U-Van ABS/TCS 1998)

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check

2

  1. Turn the ignition switch to the RUN position.
  2. Observe the ABS warning indicator.

Does the ABS warning indicator turn on for 3 seconds and then turn off?

--

Go to Diagnostic System Check

Go to Step 3

3

  1. Turn the ignition switch to the OFF position.
  2. Install a Scan Tool .
  3. Turn the ignition switch to the RUN position, engine OFF.
  4. Select Special Functions on the Scan Tool .
  5. Select Lamp Test on the Scan Tool .
  6. Use the Scan Tool in order to turn on the amber ABS warning indicator.

Did the amber ABS warning indicator turn on?

--

Go to Step 4

Go to Step 5

4

  1. Select Special Functions on the Scan Tool .
  2. Select Lamp Test on the Scan Tool .
  3. Use the Scan Tool in order to flash the amber ABS warning indicator.

Did the amber ABS warning indicator flash?

--

Go to Step 12

Go to Step 5

5

  1. Disconnect the electronic brake control module (EBCM)/ electronic brake and traction control module (EBTCM) connector C1.
  2. Turn the ignition switch to the RUN position.

Is the ABS warning indicator on?

--

Go to Step 11

Go to Step 6

6

Inspect for a grounded circuit 867 between the instrument panel cluster connector C1 terminal N and the EBCM/EBTCM connector C1 terminal A7.

Is the circuit grounded?

--

Go to Step 9

Go to Step 7

7

Inspect the ABS warning indicator bulb and the bulb connection.

Is the bulb connection OK?

--

Go to Step 10

Go to Step 8

8

Replace the ABS warning indicator bulb.

Is the repair complete?

--

Go to Diagnostic System Check

--

9

  1. Repair the short to ground in circuit 867.
  2. Perform other repairs, as needed.

Is the repair complete?

--

Go to Diagnostic System Check

--

10

Replace the instrument cluster. Refer to Instrument Panel (IP) Cluster Replacement in Instrument Panel, Gauges and Console.

Is the repair complete?

--

Go to Diagnostic System Check

--

11

Replace the EBCM/EBTCM. Refer to Electronic Brake and Traction Control Module Replacement .

Is the repair complete?

--

Go to Diagnostic System Check

--

12

The malfunction is intermittent or not present at this time.

Is the repair complete?

--

Go to Diagnostic Aids

Go to Diagnostic System Check