GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The pressure control solenoid 1 (PCS1) is a pressure proportional to current (PCC) solenoid used to control on-coming, off-going and holding pressure to any 1 of the 5 clutches. The transmission control module (TCM) provides voltage to the main modulation (MAIN MOD), torque converter clutch (TCC) and PCS1 through a separate solid-state device called high side driver 1 (HSD1). The TCM regulates the amount of current to the PCS1 by switching the low side driver ON and OFF.

DTC P2730 is a type A DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2730 Pressure Control Solenoid 1 (PCS1) Control Circuit High (A)

Conditions for Running the DTC

    • DTC P0658 and P0659 are not active.
    • The components are powered and ignition voltage is greater than 9.0 volts and less than 18 volts.
    • Engine speed is greater than 200 RPM and less than 7,500 RPM for 5 seconds.
    • TCM initialization is in process.
    • Engine crank time is not extended.

Conditions for Setting the DTC

DTC P2730 sets when the TCM detects a short to voltage on the PCS1 circuit for greater than 2 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 P2730 is stored in TCM history.
    • The TCM inhibits MAIN MOD.
    • The TCM inhibits torque converter clutch (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.

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.
  4. Turn ON the ignition, with the engine OFF.
  5. Using the DMM, measure voltage between connector terminal 55 and ground.
  6. Using the scan tool, command PCS1 ON.

Is the voltage within the specified value when the PCS1 is commanded ON?

Less than battery voltage

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 4

4

  1. Turn the ignition OFF.
  2. Disconnect the TCM from the J 39700 . Additional DTCs may set.
  3. Turn ON the ignition, with the engine OFF.
  4. Using the DMM, measure voltage at terminal 55 and ground.

Is the voltage greater than the specified value?

0 V

Go to Step 5

Go to Testing for Intermittent Conditions and Poor Connections

5

  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 engine side of the AT inline 20-way connector.
  4. Turn ON the ignition, with the engine OFF.
  5. Using the DMM and the J 35616 GM terminal test kit, measure for voltage at terminal M and ground of the J 44152 . Refer to Automatic Transmission Inline Harness Connector End View .

Is voltage greater than the specified value?

0 V

Go to Step 8

Go to Step 6

6

  1. Connect the AT inline 20-way connector.
  2. Remove the transmission oil pan. Refer to Oil Pan Replacement .
  3. Remove the AT internal wiring harness at the PCS1 connector.
  4. Using the DMM, measure for voltage at terminal 2 of the PCS1 and ground.

Is the voltage greater than the specified value?

0 V

Go to Step 9

Go to Step 7

7

  1. Disconnect the PCS1 from the internal wiring harness.
  2. Using the DMM, measure PCS1 resistance.

Is the resistance within the specified value?

5.05 ohms at 20°C (68°F)

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 10

8

Test the PCS1 circuit between the TCM and the AT inline 20-way connector for a short to voltage. Refer to Testing for a Short to Voltage .

Did you find and correct the condition?

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Go to Step 11

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9

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

Did you complete the replacement?

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Go to Step 11

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10

Replace the PCS1. Refer to Control Valve Solenoid Replacement .

Did you complete the replacement?

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Go to Step 11

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11

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 P2730.

Has the test run and passed?

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Go to Step 12

Go to Step 2

12

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