GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1998 🢒 Trans Sport Ext. 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C1324 EBTCM to PCM Requested Torque Circuit Malfunction

Object Number: 337261 Size: SF
ABS Components
Antilock Brake System Schematics
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The traction control system uses the antilock brake system in conjunction with the PCM fuel and ignition controls to limit drive wheel slippage during acceleration. The PCM controlled portion of the traction control system reduces engine torque by performing one or both of the following actions:

    • Retarding the spark timing and alternating the air/fuel ratio
    • Shutting off up to three injectors

The EBCM/EBTCM sends a torque request to the PCM via a Pulse Width Modulated (PWM) signal requesting the desired torque level for proper traction control system operation (CKT 463). The PCM then provides a delivered torque PWM signal (CKT 464) informing the EBCM/EBTCM how much actual torque the engine produces.

Conditions for Setting the DTC

DTC C1324 will set when one of the following concussions occurs:

    • A malfunction exists in the delivered torque circuit (CKT 463).
    • The signal is out of range.

Action Taken When the DTC Sets
    • A malfunction DTC stores.
    • The TCS disables.
    • The amber TCS indicator turns on.

Conditions for Clearing the DTC
    • The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTC function is used.
    • 100 drive cycles pass with no DTC detected.

Diagnostic Aids

Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction. Refer to the Scan Tool manual or Scan Tool Diagnostics located in this section for the procedure.

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

Using the scan tool, inspect for any stored PCM codes.

Are any PCM codes stored?

--

Go to Powertrain On Board Diagnostic (OBD) System Check

Go to Step 3

3
  1. Turn the ignition switch to the ON position.
  2. Observe the traction control display on the Scan Tool .

Is the BTCM to PCM requested torque at or near the specified value?

100%

Go to Step 5

Go to Step 4

4
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the electronic brake and traction control module (EBTCM).
  3. Turn the ignition switch to the ON position.
  4. Use a J 39200 DMM in order to measure the voltage between the TCS desired torque circuit at the EBTCM harness connector and ground.

Does the voltage measure the specified value?

5V

Go to Step 5

Go to Step 7

5
  1. Turn the ignition switch to the OFF position.
  2. Disconnect connector C101.
  3. Use a J 36169-A in order to connect the TCS desired torque circuit at the EBTCM harness connector and ground.
  4. Turn the ignition switch to the RUN position.
  5. Observe the frequency on the J 39200 DMM.

Is the frequency within the specified range?

120-135 Hz

Go to Step 6

Go to Step 8

6
  1. Set the J 39200 DMM to the AC% duty cycle.
  2. Connect the J 39200 DMM between the TCS desired torque circuit and ground. Measure the duty cycle.
  3. Turn the ignition switch to the ON position.
  4. Observe the duty cycle on the digital multimeter.

Is the duty cycle between the specified values?

10-95%

Go to Step 10

Go to Step 8

7
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the PCM.
  3. Turn the ignition switch to the ON position.
  4. Inspect the TCS desired torque circuit for one of the following conditions:
    5. • An open
    • A short to ground
    • A short to voltage
  5. Repair any of the above conditions, as needed.

Did you find and repair any conditions?

--

Go to Step 12

Go to Step 10

8
  1. Inspect a poor connection at the EBTCM.
  2. Repair any poor connections, as needed.

Did you find and repair any conditions?

--

Go to Step 12

Go to Step 9

9

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

Is the repair complete?

Go to Step 12

10
  1. Inspect for a poor connection at the PCM.
  2. Repair a poor connection, as needed.

Did you find and repair a poor connection?

--

Go to Step 12

Go to Step 11

11
  1. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .
  2. Program the PCM. Refer to Powertrain Control Module Replacement/Programming .

Is the repair complete?

--

Go to Step 12

--

12
  1. Clear the DTCs.
  2. Turn the ignition switch to the ON position.
  3. Observe the traction control (EBTCM to PCM requested) torque on the scan tool.

Is the traction control desired torque at or near the specified value?

100%

Go to Diagnostic System Check

Go to Step 3