GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The throttle position signal is used by the ASM to control the actual throttle position that is requested by the EBCM.

Conditions for Setting the DTC

    • DTC C0237 will set if the ASM is not receiving a reference voltage.
    • DTC C0237 will set if the reference signal is outside of a specified range.

Action Taken When the DTC Sets

    • A malfunction DTC is stored.
    • The TCS is disabled.
    • The amber TCS indicator will turn on.

Conditions for Clearing the DTC

    • Condition for DTC is no longer present and scan tool clear DTC function is used.
    • 100 ignition cycles have passed with no DTCs detected.

Diagnostic Aids

    • It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
    • If an intermittent malfunction exists refer to Inducing Intermittent Fault Conditions in Wiring Systems.

Test Description

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

  1. This step checks for an open in CKT 417.

  2. This step checks for an open in CKT 596.

  3. This step checks for an open in CKT 452.

DTC C0237 TCS Throttle Position Signal Malfunction

Step

Action

Value(s)

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference:

Antilock Brake System Connector End Views ABS Connector End Views

1

Was the Diagnostic System Check performed?

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Go to Step 2

Go to Diagnostic System Check - ABS

2

Are any PCM TPS DTC(s) set?

--

Go to Diagnostic System Check - Engine Controls in Engine Controls

Go to Step 3

3

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the PCM connector C2.
  3. Disconnect the TPS connector.
  4. Disconnect the ASM connector.
  5. Using the J 39200 DMM, measure the resistance between terminal 40 of the ASM harness connector and the TPS harness connector terminal C.

Is the resistance within the range specified in the value(s) column?

0-5ohms

Go to Step 5

Go to Step 4

4

Repair CKT 417 for an open or high resistance. Refer to Wiring Repairs .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

5

Using the J 39200 DMM, measure the resistance between terminal 41 of the ASM harness connector and the TPS harness connector terminal A.

Is the resistance within the range specified in the value(s) column?

0-5ohms

Go to Step 7

Go to Step 6

6

Repair CKT 596 for an open or high resistance. Refer to Wiring Repairs .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

7

Using the J 39200 DMM, measure the resistance between terminal 43 of the ASM harness connector and the TPS harness connector terminal B.

Is the resistance within the range specified in the value(s) column?

0-5ohms

Go to Step 9

Go to Step 8

8

Repair CKT 452 for an open or high resistance. Refer to Wiring Repairs .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

9

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

Is the replacement complete?

--

Go to Diagnostic System Check - ABS

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