GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 GTO 🢒 DTC 🢒 DTC 65

Circuit Description

The throttle relaxer assembly is controlled by the accelerator and servo control module (ASM).

Conditions for Running the DTC

DTC 65 can be set anytime the ignition switch is in the ON position.

Conditions for Setting the DTC

The electronic brake control module (EBCM) detects one of the following conditions in the throttle relaxer circuitry:

    • An open or high resistance
    • A short to ground
    • A short to voltage

Action Taken When the DTC Sets
    • The EBCM disables the traction control system for the remainder of the ignition cycle.
    • The TRAC OFF warning indicator turns ON.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.

Diagnostic Aids

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

    • An open, high resistance, or a short in the ASM motor + circuit
    • An open, high resistance, or a short in the ASM motor - circuit
    • An open or high resistance in the ASM ground circuits
    • An open, high resistance or short to ground in the ASM battery voltage circuits
    • An throttle relaxer assembly malfunction
    • An internal ASM malfunction

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The numbers below refer to step numbers on the diagnostic table.

  1. This step tests the ground circuits of the ASM for an open or high resistance.

    2.

  2. This step tests the throttle relaxer assembly.

    3.

  3. This step tests the motor + circuits of the ASM for an open or high resistance.

    4.

  4. This step tests the motor - circuits of the ASM for an open or high resistance.

    5.

  5. This step tests the motor + circuits of the ASM for a short to ground.

    6.

  6. This step tests the motor - circuits of the ASM for a short to ground.

    7.

  7. This step tests the motor + circuits of the ASM for a short to voltage.

    8.

  8. This step tests the motor - circuits of the ASM for a short to voltage.

Step

Action

Value(s)

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform A Diagnostic System Check - ABS?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

Is DTC 65 set as a current DTC?

--

Go to Step 3

Go to Diagnostic Aids

3

  1. Turn OFF the ignition.
  2. Disconnect the accelerator and servo control module (ASM) harness connector.
  3. Measure the resistance between the ground circuits of the ASM and ground. Refer to Circuit Testing in Wiring Systems.

Does the resistance for both circuits measure as specified?

0-5 ohms

Go to Step 4

Go to Step 12

4
  1. Turn ON the ignition.
  2. Measure the voltage between the battery positive voltage circuits of the ASM and ground. Refer to Circuit Testing in Wiring Systems.

Does the voltage for both circuits measure as specified?

Battery Voltage

Go to Step 5

Go to Step 13

5

  1. Turn OFF the ignition.
  2. Disconnect the throttle relaxer assembly harness connector.
  3. Disconnect the cables from the throttle relaxer. Refer to Accelerator Control Cable Replacement in Engine Controls - 5.7L.
  4. Rotate the pulleys on the throttle relaxer assembly and release. Repeat this three times.
  5. Measure the resistance between the throttle relaxer assembly terminals. Refer to Circuit Testing in Wiring Systems.

Does the resistance measure as specified?

0.5-10 ohms

Go to Step 6

Go to Step 14

6

  1. Turn OFF the ignition.
  2. Disconnect the accelerator and servo control module (ASM) and the throttle relaxer assembly harness connectors.
  3. Measure the resistance of the motor + circuits between the ASM and throttle relaxer assembly connectors. Refer to Circuit Testing in Wiring Systems.

Does the resistance for both circuits measure as specified?

0-5 ohms

Go to Step 7

Go to Step 15

7

Measure the resistance of the motor - circuits between the ASM and throttle relaxer assembly connectors. Refer to Circuit Testing in Wiring Systems.

Does the resistance for both circuits measure as specified?

0-5 ohms

Go to Step 8

Go to Step 16

8

  1. Connect the throttle relaxer assembly harness connector.
  2. Measure the resistance of the motor + circuit of the ASM to ground. Refer to Circuit Testing in Wiring Systems.

Does the resistance measure as specified?

infinite ohms

Go to Step 9

Go to Step 15

9

Measure the resistance of the motor - circuit of the ASM to ground. Refer to Circuit Testing in Wiring Systems.

Does the resistance measure as specified?

infinite ohms

Go to Step 10

Go to Step 16

10

  1. Connect the accelerator and servo control module harness connector.
  2. Disconnect the throttle relaxer assembly harness connector.
  3. Turn ON the ignition.
  4. Measure the voltage of the motor + circuit at the throttle relaxer assembly harness connector. Refer to Circuit Testing in Wiring Systems.

Does the voltage measure as specified?

Greater than 1 V

Go to Step 15

Go to Step 11

11

With the ignition ON, measure the voltage of the motor - circuit of the throttle relaxer assembly harness connector. Refer to Circuit Testing in Wiring Systems.

Does the voltage measure as specified?

Greater than 1 V

Go to Step 16

Go to Step 17

12

Locate and repair the open or high resistance in the ASM ground circuits. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 18

--

13

Locate and repair the open, high resistance or short to ground in the ASM battery voltage circuits. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 18

--

14

Replace the Throttle Relaxer Assembly. Refer to Accelerator and Servo Control Module Replacement .

Did you complete the replacement?

--

Go to Step 18

--

15

Locate and repair the open, high resistance or short in the ASM motor + circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 18

--

16

Locate and repair the open, high resistance or short in the ASM motor - circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 18

--

17

Replace the Accelerator and Servo Control Module (ASM). Refer to Accelerator and Servo Control Module Replacement .

Did you complete the replacement?

--

Go to Step 18

--

18
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK