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 HSD1, then DTC P1831 sets. DTC P1831 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P1831 Pressure Control (PC)/Shift Lock Solenoid Control Circuit Low Voltage
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 HSD1 circuit when the HSD1 is commanded ON.
Action Taken When the DTC Sets
| • | The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL). |
| • | SERVICE VEHICLE SOON displays on the driver information center (DIC). |
| • | The TCM commands maximum line pressure. |
| • | The TCM freezes transmission adaptive functions. |
| • | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record. |
| • | The TCM stores DTC P1831 in TCM history. |
Conditions for Clearing the DTC/DIC
| • | The TCM clears the DIC when the condition no longer exists. |
| • | A scan tool can clear the DTC. |
| • | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring. |
| • | The TCM cancels the DTC 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 - Vehicle? | -- | Go to Step 2 | |||||
2 |
Important:
Did DTC P1831 reset? | -- | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections | ||||
3 |
Did DTC P1831 reset? | -- | Go to Step 4 | Go to Step 5 | ||||
4 |
Did you find a condition? | -- | Go to Step 8 | Go to Step 7 | ||||
5 | Test the HSD1 circuit between the AT inline 20-way connector and the pressure control solenoid for a short to ground. Refer to Testing for Short to Ground . Did you find a condition? | -- | Go to Step 9 | Go to Step 6 | ||||
6 | Replace the shorted pressure control solenoid. Refer to Pressure Control Solenoid Valve Replacement . Is the action complete? | -- | Go to Step 10 | -- | ||||
7 | Replace the TCM. Refer to Control Module References for replacement, setup and programming. Is the action complete? | -- | Go to Step 10 | -- | ||||
8 | Repair the short to ground on the HSD1 circuit. Refer to Wiring Repairs . Is the action complete? | -- | Go to Step 10 | -- | ||||
9 | Replace the internal transmission electrical harness. Refer to Transmission Internal Electrical Harness Replacement . Is the action complete? | -- | Go to Step 10 | -- | ||||
10 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | 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? | -- | System OK |
