Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category |
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 make sure that it is functioning properly.
When the TCM detects a short to voltage on HSD2, then DTC P1834 sets. DTC P1834 is a type B DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P1834 Torque Converter Clutch (TCC)/Shift Solenoid (SS) Control Circuit High Voltage
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The TCM detects at least 6.4 volts at the HSD2 terminal prior to commanding the HSD2 ON.
Action Taken When the DTC Sets
| • | The TCM requests the engine control module (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. |
| • | 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 P1834 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 - Vehicle? | -- | Go to Step 2 | |||||
2 |
Important:
Did DTC P1834 reset? | -- | Go to Step 3 | Go to Intermittent Conditions | ||||
3 |
Is the voltage greater than the specified value? | 6.4 volts | Go to Step 4 | Go to Step 5 | ||||
4 | Repair the short to voltage on the solenoid supply voltage circuit. Refer to Wiring Repairs . Is the action complete? | -- | Go to Step 6 | -- | ||||
5 | Replace the TCM. Refer to Control Module References for replacement, set-up and programming. Is the action complete? | -- | Go to Step 6 | -- | ||||
6 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 7 | Go to Step 2 | ||||
7 | 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 |
