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 TCS warning indicator in order to identify either of the following conditions:

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

The EBCM/EBTCM must provide a ground in order to turn the amber TCS warning indicator off because of Malfunction Indicator Lamp Control Module (lamp driver module) in the circuit. Because of the circuitry in the Lamp Driver Module (LDM), only external malfunctions can be detected. As a result, the LDM is not diagnosable. If CKT 1572 is open, the TCS 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 TCS warning indicator will remain off. The TCS warning indicator will remain off because the integral LDM input will be grounded. DTC C1311 will set if any of the following conditions exist:

    • An open in CKT 1572
    • A short to ground on CKT 1572
    • A short to voltage in CKT 1572

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 TCS 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.

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 OFF position.
  2. Disconnect the 24-way EBCM/EBTCM connector C1.
  3. Turn the ignition switch to the RUN position, engine OFF.

Is the TCS indicator on?

--

Go to Step 6

Go to Step 3

3

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the malfunction indicator lamp traction control module (MIL TCM) from the MIL TCM connector.
  3. Connect a fused jumper wire with a 3A fuse between the MIL TCM connector terminal E and ground.
  4. Turn the ignition switch to the RUN position, engine OFF.

Is the TCS indicator on?

--

Go to Step 4

Go to Step 7

4

  1. Turn the ignition switch to the OFF position.
  2. Remove the jumper wire from the MIL TCM connector terminal E.
  3. Use the J 39200 in order to measure the resistance between the MIL TCM connector terminal D and ground.

Is the resistance within the specified range?

0-2ohms

Go to Step 5

Go to Step 10

5

  1. Turn the ignition switch to the RUN position, engine OFF.
  2. Use the J 39200 in order to measure the voltage between the MIL TCM connector terminal B and ground.

Is the voltage equal to or greater than the specified voltage?

10V

Go to Step 12

Go to Step 11

6

  1. Inspect the following components:
  2. • The 24-way EBCM/EBTCM connector C1
    • The 24-way EBCM/EBTCM harness connector C1
    • The MIL TCM connector
  3. Inspect these components for the following conditions:
  4. • Terminal damage
    • Poor terminal contact
    • Terminal corrosion

Are there signs of poor terminal contact, terminal corrosion, or damaged terminals?

--

Go to Step 13

Go to Step 16

7

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the instrument panel cluster connector C2.
  3. Use the J 39200 in order to measure the resistance between the MIL TCM connector terminal E and the instrument panel cluster connector C2 terminal A.

Is the resistance within the specified range?

0-2ohms

Go to Step 8

Go to Step 14

8

  1. Turn the ignition switch to the RUN position, engine OFF.
  2. Use the J 39200 in order to measure the voltage between the MIL TCM connector harness terminal E and ground.

Is the voltage within the specified range?

0-2V

Go to Step 9

Go to Step 15

9

Inspect the instrument panel cluster connector for the following conditions:

    • Terminal damage
    • Poor terminal contact
    • Terminal corrosion

Are there signs of poor terminal contact, terminal corrosion, or damaged terminals?

--

Go to Step 13

Go to Instrument Panel Cluster

10

Repair the open or high resistance in CKT 1550.

Is the repair complete?

--

Go to Diagnostic System Check

--

11

Repair the open or high resistance in CKT 39.

Is the repair complete?

--

Go to Diagnostic System Check

--

12

Replace the Lamp Driver Module. Refer to Lamp Driver Module Replacement .

Is the repair complete?

--

Go to Diagnostic System Check

--

13

Replace all of the terminals that exhibit signs of poor terminal contact, terminal corrosion, or damaged terminal(s).

Is the repair complete?

--

Go to Diagnostic System Check

--

14

Repair the open or high resistance in CKT 1808.

Is the repair complete?

--

Go to Diagnostic System Check

--

15

Repair the short to voltage in CKT 1808.

Is the repair complete?

--

Go to Diagnostic System Check

--

16

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

Is the repair complete?

--

Go to Diagnostic System Check

--