P0973

DTC P0973





Circuit Description
The reverse, 1st shift solenoid (SS) valve (S1) is commanded ON in NEUTRAL and first gear. The reverse, 1st SS valve (S1) controls transmission fluid pressure acting on the neutral relay and M1 shift valves to position the valves for the appropriate gear. The reverse, 1st SS valve (S1) is a normally open exhaust valve located on the front control valve body. The solenoid is case grounded. The output driver module (ODM), within the transmission control module (TCM), commands the solenoid ON or OFF by providing voltage. When the reverse, 1st SS valve (S1) is commanded ON, the TCM senses high voltage. When the reverse, 1st SS valve (S1) is commanded OFF, the TCM senses low voltage.

If the TCM detects a continuous short to ground in the reverse, 1st SS valve (S1) circuit, then DTC P0973 sets. DTC P0973 is a type A DTC.

DTC Descriptor
This diagnostic procedure supports the following DTC:

DTC P0973 Shift Solenoid (SS) 1 Control Circuit Low Voltage

Conditions for Running the DTC
^ The engine speed is greater than 400 RPM.
^ The system voltage is 10.2 - 15.5 volts.
^ Trans. protection mode is OFF.
^ The TCM commands the reverse, 1st SS valve (S1) ON.

Conditions for Setting the DTC
The reverse, 1st SS valve (S1) feedback circuit indicates a continuous short to ground for 0.5 seconds.

Action Taken When the DTC Sets
^ The TCM requests the powertrain control module (PCM) to illuminate the malfunction indicator lamp (MIL).
^ The TCM turns the Trans. Protection Mode ON.
^ The transmission will operate in 5th gear when the transmission is shifted into D or I range and 2nd gear when shifted into L range.
^ The line pressure is at maximum.
^ The torque converter clutch (TCC) is disabled.
^ The TCM freezes the transmission adaptive functions.
^ The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM 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 Record.
^ The TCM stores DTC P0973 in TCM history.

Conditions for Clearing the MIL/DTC
^ The PCM 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 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 DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Test Description

Step 1 - Step 7:

Step 8 - Step 12:

The numbers below refer to the step numbers on the diagnostic table.
3. This step tests the TCM and the wiring to the transmission.
5. This step verifies that the circuit has the correct resistance.