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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1997 🢒 Catera 🢒 Brakes 🢒 ABS Brakes - Bosch2sh 🢒 No Communication with Electronic Brake and Traction Control Module

Object Number: 174415 Size: SF
ABS Components
Antilock Brake System Schematics

Circuit Description

The keyword 82 serial data line to the EBTCM is one of three communication protocols used by the various control modules on the vehicle. The primary function of the keyword 82 serial data line to the EBTCM is for diagnostic communication to the scan tool.

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.

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

    • 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. If the scan tool cannot communicate with other modules on the serial data line, there is a concern with the serial data line circuit.

    2.

  2. This step checks for an open or high resistance in the EBTCM ground circuit.

    3.

  3. This step checks for an open or short to ground in the EBTCM ignition feed circuit.

    4.

  4. This step checks for an open or high resistance in the Keyword 82 serial data line.

No Communication with EBTCM

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go toA 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. Attempt to communicate with the Heating and Air Conditioning or the Supplemental Inflatable Restraint (SIR) in Body or Variable Effort Steering (VES) in Chassis.

Can the scan tool communicate with other modules on the Keyword 82 serial data line?

--

Go to Step 3

Go to Data Link Communications System Check in Wiring Systems for diagnosis

3
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the 4-way EBTCM connector C2.
  3. Use a J 39200 DMM to measure the resistance between the 4-way EBTCM harness connector C2, terminal 3 and a good ground.

Is the resistance within the specified range?

0-2 ohms

Go to Step 4

Go to Step 7

4
  1. Turn the ignition switch to the RUN position with the engine off.
  2. Use a J 39200 DMM to measure the voltage between the 4-way EBTCM harness connector C2, terminal 1 and ground.

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

10V

Go to Step 5

Go to Step 8

5
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the 25-way EBTCM connector C1.
  3. Install the J 39700 Universal Breakout Box with the J 39700-250 Cable Adapter to the EBTCM harness connector only.
  4. Use a J 39200 DMM to measure the resistance between the J 39700 terminal 15 and the DLC terminal 12.

Is the resistance within the specified range?

0-2 ohms

Go to Step 6

Go to Step 9

6

Replace the EBTCM. Refer to EBTCM Replacement .

Is the repair complete?

--

Go to A Diagnostic System Check

--

7

Repair an open or repair a high resistance in the EBTCM ground circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to A Diagnostic System Check

--

8

Repair an open or repair a short to ground in the ignition feed circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to A Diagnostic System Check

--

9

Repair an open or repair a high resistance in the Keyword 82 serial data line. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to A Diagnostic System Check

--