P0758

Diagnostic Chart:

Diagnostic Chart (cont'd):

Wiring Diagram:

Circuit Description
The 2-3 Shift Solenoid Valve (2-3 SS Valve) controls fluid acting on the 2-3 shift valve. The solenoid is a normally-open exhaust valve used with the 1-2 Shift Solenoid Valve in order to allow four different shifting combinations. The 2-3 SS Valve attaches to the control valve body within the transmission. The ignition voltage goes directly to the 2-3 SS Valve. The VCM controls the 2-3 SS Valve by providing the ground path through circuit 1223.

When the VCM detects a continuous open or short in the 2-3 SS valve circuit or the 2-3 SS Valve, then DTC PO758 sets. DTC P0758 is a type D DTC. For California emissions vehicles, DTC P0758 is a type A DTC.

Conditions for Setting the DTC

^ No system voltage DTC PO560.
^ The ignition is ON.
^ The VCM commands the 2-3 SS Valve On, and the voltage remains high (B+).
^ The VCM commands the 2-3 SS Valve Off, and the voltage remains low (0 volts).
^ All conditions are met for 5 seconds.

Action Taken When the DTC Sets

^ The VCM commands an immediate landing to second gear.
^ The VCM commands maximum line pressure.
^ The VCM freezes shift adapts form being updated.
^ The VCM illuminates the Malfunction Indicator Lamp (MIL) for California emission vehicles.

Conditions for Clearing the DTC

^ For California emissions vehicles, the VCM turns OFF the MIL after three consecutive ignition cycles without a failure reported.
^ A scan tool can clear the DTC from the VCM history. The VCM clears the DTC from the VCM history if the vehicle completes 40 warm-up cycles without a failure reported.
^ The VCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the VCM.

Diagnostic Aids

^ Inspect the wiring for poor electrical connections at the VCM. Inspect the wiring for poor electrical connections at the transmission 20-way connector. Look for the following conditions:

- A bent terminal
- A backed out terminal
- A damaged terminal
- Poor terminal tension
- A chafed wire
- A broken wire inside the insulation

^ When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.
^ First diagnose and clear any engine DTCs or TP Sensor codes that are present. Then inspect for any transmission DTCs that may have reset. Refer to Shift Solenoid Valve State and Gear Ratio table.

Test Description
The numbers below refer to the step numbers on the diagnostic table.

4. This step tests the function of the 2-3 SS Valve and the transmission internal wiring harness.
5. This step tests the power to the 2-3 SS Valve from the ignition through the fuse.
7. This step tests circuit 1223 form the transmission 20-way connector to the VCM for an open.
8. This step tests circuit 1223 from the transmission 20-way connector to the VCM for a short to ground.