GM Service Manual Online
For 1990-2009 cars only

Object Number: 1285490  Size: MF
Master Electrical Component List
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice

Circuit Description

The transmission control module (TCM) provides voltage to the pressure control solenoid, the shift solenoids, and the TCC PWM solenoid through two separate solid-state devices called High Side Drivers, called HSD1 and HSD2. HSD1 provides electrical power to the pressure control solenoid. HSD2 provides power to the shift solenoids. A normal function of the TCM is to run tests on each driver to ensure that it is functioning properly.

When the TCM detects a short to ground on HSD2, then DTC P1833 sets. DTC P1833 is a type B DTC.

Conditions for Running the DTC

The engine run time is greater than 5 seconds.

Conditions for Setting the DTC

The TCM detects a short to ground on the HSD2 circuit when the HSD2 is commanded ON.

Action Taken When the DTC Sets

    • The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
    • The TCM turns off power to all solenoids.
    • The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear.
    • The TCM commands maximum line pressure.
    • The TCC is disabled.
    • Powertrain braking is disabled.
    • The TCM freezes transmission adaptive functions.
    • At the time of the first failure, the TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
    • At the time of the second failure, the ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as a Freeze Frame.
    • The TCM stores DTC P1833 in TCM history.

Conditions for Clearing the MIL/DTC

    • The ECM turns OFF the MIL after the sixth consecutive drive trip in which the TCM does not send a MIL illumination request.
    • A scan tool can clear the MIL/DTC.
    • The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
    • The TCM cancels the default actions when the ignition is OFF long enough in order to power down the TCM.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check - Automatic Transmission?

--

Go to Step 2

Go to Diagnostic System Check - Automatic Transmission

2

  1. Install a 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 ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM.
       • Using the Clear Info function erases stored DTCs in both the ECM and TCM.

  4. Record the DTC Freeze Frame and Failure Records.
  5. Clear the DTC.
  6. Turn OFF the ignition for at least 30 seconds.
  7. Start the engine.

Did DTC P1833 reset?

--

Go to Step 3

Go to Intermittent Conditions in Engine Controls - 2.6L and 3.2L or Intermittent Conditions in Engine Controls - 3.6L (LY7)

3

  1. Turn OFF the ignition.
  2. Disconnect the AT inline 20-way connector.
  3. Turn ON the ignition with the engine OFF.
  4. Clear the DTC.
  5. Turn OFF the ignition for at least 30 seconds.
  6. Start the engine. Additional DTCs may set.

Did DTC P1833 reset?

--

Go to Step 4

Go to Step 5

4

  1. Disconnect the TCM.
  2. Test the solenoid supply voltage circuit between the AT inline 20-way connector and the TCM for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 7

5

Test the solenoid supply voltage circuit between the AT inline 20-way connector and each individual solenoid for a short to ground. Refer to Testing for Short to Ground in Wiring Systems.

Did you find a condition?

--

Go to Step 8

Go to Step 6

6

Replace the shorted solenoid. Refer to 1-2 Shift Solenoid Valve Replacement , 2-3 Shift Solenoid Valve Replacement , 4-5 Shift Solenoid Valve Replacement , or Torque Converter Clutch Solenoid Replacement , as applicable.

Is the action complete?

--

Go to Step 9

--

7

Replace the TCM. Refer to Transmission Control Module Replacement .

Is the action complete?

--

Go to Step 9

--

8

Replace the internal transmission electrical harness. Refer to Transmission Internal Electrical Harness Replacement .

Is the action complete?

--

Go to Step 9

--

9

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Start the engine.
  4. Select Specific DTC.
  5. Enter DTC P1833.

Has the test run and passed?

--

Go to Step 10

Go to Step 2

10

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?

--

Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 2.6L and 3.2L or Diagnostic Trouble Code (DTC) List in Engine Controls - 3.6L (LY7)

System OK