GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Holden 🢒 2005 🢒 Caprice WL 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 5L40-E/5L50-E 🢒 DTC P1831

Circuit Description

The Transmission Control Module (TCM) provides voltage to the pressure control solenoid, the shift solenoids and the torque converter clutch pulse width modulated 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 and the torque converter clutch solenoid. 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 HSD1 driver circuit, then DTC P1831 sets, which is a type 'C' DTC.

Conditions for Running the DTC
    • Ignition voltage is between 8.0 and 18.0 volts.
    • Engine is running between 450 and 6,800 RPM for at least 5 seconds.

Conditions for Setting the DTC

The TCM detects a short to ground on the HSD1 circuit when the HSD1 is commanded on.

Action Taken When the DTC Sets
    • The TCM does not request the Powertrain Interface Module to illuminate the Check Powertrain Malfunction Indicator Lamp (MIL).
    • The TCM turns off the pressure control solenoid (causing maximum line pressure).
    • The TCM freezes the transmission adaptive learning function.
    • At the time of the first failure, the TCM records the operating conditions when the 'Conditions for Setting the DTC' have been met. The TCM stores this information as a failure record.
    • The TCM stores DTC P1831 into TCM history.

Conditions for Clearing the DTC
    • Tech 2 can clear the DTC.
    • The TCM clears the DTC from its memory (history DTC) if the vehicle completes 40 warm-up cycles without a non-emission related DTC occurring.
    • The TCM cancels the default actions when the ignition is off long enough to power down the TCM.

Step

Action

Values

Yes

No

Schematic Reference: Automatic Transmission Controls Schematics

For information on testing wiring faults, refer to Wiring Systems.

1

Has the Diagnostic System Check - Automatic Transmission been completed?

--

Go to Step 2

Go to Diagnostic System Check - Automatic Transmission

2
  1. Connect Tech 2 to the DLC.
  2. Ignition ON, engine OFF.
  3. Clear the DTCs.
  4. Turn ignition OFF for at least 30 seconds.
  5. Start the engine.

Did DTC P1831 reset?

--

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3
  1. Turn ignition OFF.
  2. Disconnect the transmission wiring harness connector X121-X1 from the transmission 20-way connector.
  3. Turn ignition ON, with the engine OFF.
  4. Clear the DTCs.
  5. Turn ignition off for at least 30 seconds
  6. Start the engine (additional DTCs may have set).

Did DTC P1831 reset?

--

Go to Step 4

Go to Step 5

4
  1. Ignition OFF.
  2. Disconnect the TCM.
  3. Using a digital ohmmeter, check the HSD1 circuit 1228 between the transmission wiring harness TCM connector A112-T68, terminal X1-3 and the transmission wiring harness connector X121-X1, terminal X1-13 for a short to ground condition.

Did you find a short to ground condition?

--

Go to Step 8

Go to Step 7

5
  1. Ignition OFF.
  2. Remove transmission fluid pan. Refer to Transmission Fluid Pan and Filter Assembly Removal.
  3. Inspect transmission internal wiring harness for any sign of damage.
  4. Using a digital ohmmeter, check the HSD1 circuit 1228 for a short to ground condition between the 20-way connector X121-X1a, terminal X1-13 and the pressure control solenoid terminal 'A'.

Did you find a short circuit condition?

--

Go to Step 9

Go to Step 6

6

Replace the pressure control solenoid. Refer to Pressure Control Solenoid Valve Replacement.

--

Go to Step 10

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7

Replace TCM. Refer to Transmission Control Module Replacement.

Is replacement complete?

--

Go to Step 10

--

8

Repair the short to ground on the HSD1 circuit.

Is the action completed

--

Go to Step 10

--

9

Remove and replace transmission internal wiring harness. Refer to Transmission Internal Electrical Harness Replacement.

Is replacement complete?

--

Go to Step 10

--

10
  1. Perform the following operation to verify the repair:
    2. 1.1. Select DTC on the Tech 2.
    1.2. Select Clear info.
    1.3. Start the engine.
  2. Operate the vehicle in the conditions for Running the DTC.

Has the test run and passed?

--

System OK

Go to Step 2

When all diagnosis and repairs are completed, clear all DTCs and verify correct operation.