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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1997 🢒 Catera 🢒 Brakes 🢒 ABS Brakes - Bosch2sh 🢒 ABS Indicator Always On

Object Number: 174394 Size: SF
ABS Components
Antilock Brake System Schematics

Circuit Description

This symptom table checks the state of the ABS indicator to identify a situation in which the ABS indicator is always on. The EBTCM provides a ground through the ABS indicator control circuit to turn the ABS indicator on. If the control circuit is shorted to ground the ABS indicator will always be on when the ignition switch is in the RUN position. The EBTCM provides a redundant control circuit on the 4-pin connector C2, terminal 4 in the event that the 25-pin harness connector C1 becomes disconnected from the EBTCM. If this occurs, the ABS indicator will be turned on by a ground provided on the 4-pin connector C2, terminal 4.

Diagnostic Aids

The following can cause an intermittent malfunction:

    • A poor connection can cause an intermittent malfunction.
    • Rubbed through wire insulation can cause an intermittent malfunction.
    • A wire that is broken inside the insulation can cause an intermittent malfunction.

The ABS Indicator Lamp Test function of the scan tool may be used to command the indicator while looking for an intermittent malfunction in the ABS indicator circuitry.

Check for the following in any circuit suspected of causing an intermittent malfunction:

    • Check for backed out terminals.
    • Check for improper mating.
    • Check for broken locks.
    • Check for improperly formed terminals.
    • Check for damaged terminals.
    • Check for poor terminal to wiring connections.
    • Check for physical damage to the wiring harness.

Test Description

The number(s) below refer to the step numbers on the diagnostic table.

  1. Running the scan tool Lamp Test will determine if the EBTCM can turn the indicator on and off.

    2.

  2. If the 25 pin EBTCM connector C1 is not properly retained to the EBTCM, the ABS indicator will turn on.

    3.

  3. This step checks for a short to ground in the ABS indicator circuit.

ABS Indicator On No DTC Set

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to A Diagnostic System Check

2
  1. Turn the ignition switch to the OFF position.
  2. Install a scan tool.
  3. Turn the ignition switch to the RUN position with the engine off.
  4. Use the scan tool to select Special Functions.
  5. Select and run ABS Indicator Lamp Test in Special Functions.

Was the test completed successfully?

--

Go to Step 6

Go to Step 3

3
  1. Turn the ignition switch to the OFF position.
  2. Remove the scan tool.
  3. Turn the ignition switch to the RUN position with the engine off.

Does the ABS indicator turn on and stay on?

--

Go to Step 4

Go to Step 11

4
  1. Turn the ignition switch to the OFF position.
  2. Check that the 25-way EBTCM harness connector is properly retained to the EBTCM.
  3. Turn the ignition switch to the RUN position with the engine off.

Does the ABS indicator turn on and stay on?

--

Go to Step 5

Go to A Diagnostic System Check

5
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the 25-way EBTCM connector C1.
  3. Disconnect the 4-way EBTCM connector C2.
  4. Turn the ignition switch to the RUN position with the engine off.

Does the ABS indicator turn on and stay on?

--

Go to Step 8

Go to Step 6

6
  1. Turn the ignition switch to the OFF position.
  2. Inspect the 25-way EBTCM connector C1, terminal 1 and inspect the 4-way EBTCM connector C2, terminal 4 for the following signs:
    3. • Inspect for signs of damage.
    • Inspect for signs of poor terminal contact.
    • Inspect for signs of terminal corrosion.
  3. Inspect the remaining terminals of the 25-way EBTCM connector C1, and inspect the 4-way EBTCM connector C2 for the following signs:
    4. • Inspect for signs of damage.
    • Inspect for signs of poor terminal contact.
    • Inspect for signs of terminal corrosion.

Are the following signs evident:

    • Is poor terminal contact evident?
    • Is corrosion evident?
    • Is damaged terminal(s) evident?

--

Go to Step 9

Go to Step 7

7
  1. Reconnect the 25-way EBTCM harness connector C1.
  2. Reconnect the 4-way EBTCM harness connector C2 if previously disconnected.
  3. Turn the ignition switch to the RUN position with the engine off.

Does the ABS indicator turn on and stay on?

--

Go to Step 10

Go to Step 11

8

Repair the short to ground in the ABS indicator circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to A Diagnostic System Check

--

9
  1. Repair the 25-way EBTCM connector C1.
  2. Repair the 4-way EBTCM connector C2 if necessary. Refer to Connector Repairs in Wiring Systems.

Is the repair complete?

--

Go to A Diagnostic System Check

--

10

Replace the EBTCM. Refer to EBTCM Replacement .

Is the repair complete?

--

Go to A Diagnostic System Check

--

11

The malfunction is intermittent or the malfunction is not present at this time. Refer to Diagnostic Aids on the facing page for more information.

Is the diagnosis complete?

--

Go to A Diagnostic System Check

--