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 and TCC PWM 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 an open or a short to ground on HSD1, then DTC P1831 sets. DTC P1831 is a type A DTC.
The engine run time is greater than 5 seconds.
The TCM detects an open or a short to ground on the HSD1 circuit when the HSD1 is commanded ON.
• | The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL). |
• | The TCM commands an immediate landing to 2nd gear. |
• | The TCM commands maximum line pressure. |
• | The TCM inhibits TCC engagement. |
• | The TCM commands high side driver 1 off. |
• | The TCM freezes transmission adaptive function. |
• | The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records. |
• | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records. |
• | The TCM stores DTC P1831 in TCM history. |
• | The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request. |
• | A scan tool can clear the 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 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 - Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 3.0L (L81) | ||||
2 |
Important:
Did DTC P1831 reset? | -- | Go to Step 3 | Go to Intermittent Conditions in Engine Controls - 3.0L (L81) | ||||
3 | Replace the TCM. Refer to Transmission Control Module Replacement . Is the action complete? | -- | Go to Step 4 | -- | ||||
4 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 5 | Go to Step 2 | ||||
5 | 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 - 3.0L (L81) | System OK |