GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The torque converter clutch (TCC) pressure control solenoid (PCS) is a pressure proportional to current (PCC) solenoid used to control the TCC apply and release. The transmission control module (TCM) provides voltage to the main modulation (MAIN MOD), TCC and pressure control solenoid 1 (PCS1) through a separate solid-state device called high side driver 1 (HSD1). The TCM regulates the amount of current to the TCC PCS by switching the low side driver ON and OFF.

DTC P2761 is a type A DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2761 Torque Converter Clutch (TCC) Pressure Control Solenoid (PCS) Control Circuit Open

Conditions for Running the DTC

    • DTC P0716, P0717, P0721 and P0722 are not active.
    • The components are powered and ignition voltage is greater than 9.0 volts and less than 18 volts.
    • TCM initialization is in process or engine speed is greater than 200 RPM and less than 7,500 RPM for 5 seconds.
    • The TCC is commanded ON.

Conditions for Setting the DTC

DTC P2761 sets when the TCM detects an open circuit on the TCC PCS return circuit for greater than 6 seconds.

Action Taken When the DTC Sets

    • The TCM illuminates the malfunction indicator lamp (MIL).
    • If the failure occurs while in a forward range, a shift to 1st, 3rd or 5th range is made.
    • While diagnostic response is active, if the shift selector is moved to NEUTRAL, the transmission will shift to NEUTRAL. If the shift selector is moved to REVERSE, the transmission will shift to REVERSE. If the shift selector is moved to a forward range or to REVERSE and the transmission is compromised by overspeeding or direction change, the transmission will shift to NEUTRAL.
    • DTC P2761 is stored in TCM history.
    • The TCM inhibits MAIN MOD.
    • The TCM inhibits REVERSE operation.
    • The TCM freezes shift adapts.
    • The TCM inhibits TCC engagement.

Conditions for Clearing the MIL/DTC

A scan tool can clear the code from TCM history. The TCM automatically clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without failure.

Diagnostic Aids

    • Inspect the wiring for poor electrical connections at the TCM. Inspect for the following conditions:
       - A bent terminal
       - A backed-out terminal
       - A damaged terminal
       - Poor terminal tension
       - A chafed wire
       - A broken wire inside the insulation
    • When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.
    • You may have to drive the vehicle in order to experience a condition.
    • DTC P2761 set in combination with DTC P0960 and P2727 may indicate an open in the HSD circuit.

Step

Action

Value

Yes

No

Schematic Reference: Automatic Transmission Controls Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install the scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data.

  4. Record the DTC Freeze Frame and Failure Records.
  5. Clear the DTC.
  6. Using the scan tool, measure ignition voltage.

Is voltage within the specified value?

9-18 V

Go to Step 3

Go to DTC P0562 for low voltage or DTC P0563 for high voltage

3

  1. Turn the ignition OFF.
  2. Disconnect the 80-way connector at the TCM.
  3. Install the J 39700 breakout box, the J-47275 breakout box adapter and the J 47275-1 magnetic overlay. Do not reconnect the TCM.
  4. Using the DMM, measure the resistance at terminals 11 and 78.

Is the resistance reading within the specified value?

5.05 ohms at 20°C (68°F)

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 4

4

  1. Turn the ignition OFF.
  2. Disconnect the AT inline 20-way connector. Additional DTCs may set.
  3. Install the J 44152 jumper harness (20 pins) on the transmission side of the AT inline 20-way connector.
  4. Using the DMM and the J 35616 GM terminal test kit, measure the resistance between terminals L and J of the J 44152 . Refer to Automatic Transmission Inline Harness Connector End View .

Is the resistance within the specified value?

5.05 ohms at 20°C (68°F)

Go to Step 6

Go to Step 5

5

  1. Remove the transmission oil pan. Refer to Oil Pan Replacement .
  2. Remove the AT internal wiring harness at the TCC PCS connector.
  3. Using the DMM, measure the resistance of the TCC PCS.

Is the solenoid resistance within the specified value?

5.05 ohms at 20°C (68°F)

Go to Step 7

Go to Step 8

6

Test the TCC PCS circuit between the TCM and the AT inline 20-way connector for an open condition. Refer to Testing for Continuity .

Did you find and correct the condition?

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Go to Step 10

Go to Step 9

7

Replace the AT internal wiring harness. Refer to Wiring Harness Replacement .

Did you complete the replacement?

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Go to Step 10

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8

Replace the TCC PCS. Refer to Control Valve Solenoid Replacement .

Did you complete the replacement?

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Go to Step 10

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9

Important: In most cases, the TCM is not at fault. Investigate thoroughly before replacing the TCM.

Replace the TCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

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Go to Step 10

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10

Perform the following procedure in order to verify the repair:

  1. Clear the DTC.
  2. Drive the vehicle under normal operating conditions.
  3. Select Specific DTC.
  4. Enter DTC P2761.

Has the test run and passed?

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Go to Step 11

Go to Step 2

11

With the scan tool, observe the stored information, capture info and DTC info.

Does the scan tool display any DTCs that you have not diagnosed?

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Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK