Circuit Description
The shift solenoid valve #1 is located in the control valve body of the transmission. The powertrain control module (PCM) selects the required gear by turning the appropriate solenoid ON or OFF, enabling the transmission to shift.
Shifting from 1st to O/D is performed in combination with the PCM controlling the ON and OFF switching functions of the shift solenoids. If an open or short to ground occurs in either of the solenoid valves, the PCM controls the remaining functioning shift solenoid valve to allow the vehicle to be operated smoothly in a fail safe mode.
When the PCM detects a continuous short to ground in the shift solenoid valve #1 circuit, then DTC P0973 sets. DTC P0973 is a type B DTC.
Conditions for Running the DTC
PCM detects a short in shift solenoid #1 circuit 4 times.
Conditions for Setting the DTC
DTC P0973 sets when either of the following conditions occurs:
The PCM detects a short to ground in the shift solenoid #1 circuit when the solenoid is commanded OFF.
Action Taken When the DTC Sets
| • | At the time of the first failure, the PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as a Failure Record. |
| • | The PCM illuminates the malfunction indicator lamp (MIL) during the first consecutive drive trip in which the Conditions for Setting the DTC are met. |
| • | The PCM turns off power to all solenoids, when the solenoids are off. |
| • | The PCM stores DTC P0973 in PCM history. |
Conditions for Clearing the MIL/DTC
| • | A scan tool can clear the MIL/DTC. |
| • | The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
Schematic Reference: Automatic Transmission Controls Schematics | ||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||
Important:
Does the solenoid operate? | -- | Go to Step 5 | Go to Step 3 | |||||
3 |
Did you find a condition? | -- | Go to Step 6 | Go to Step 5 | ||||
4 |
Short to ground--Refer to Testing for Short to Ground in Wiring Systems. Did you find a condition? | -- | Go to Step 7 | Go to Step 8 | ||||
5 | Replace the PCM. Refer to Powertrain Control Module Programming and Setup in Programming and Setup. Is the action complete? | -- | Go to Step 9 | -- | ||||
6 | Perform the necessary wiring repairs. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | Go to Step 9 | -- | ||||
7 | Replace the AT internal transmission wiring harness. Refer to Solenoids and Wiring Harness Replacement . Is the action complete? | -- | Go to Step 9 | -- | ||||
8 | Replace the shift solenoid valve. Refer to Solenoids and Wiring Harness Replacement . Is the action complete? | -- | Go to Step 9 | -- | ||||
9 | Perform the following procedure in order to verify the repair:
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 - Vehicle in Vehicle DTC Information | System OK | ||||
