P0758

Circuit Description

The 2-3 shift solenoid valve (2-3 SS valve) controls the transmission fluid pressure on the 2-3 shift valve. A fused circuit 1039 provides ignition voltage to the solenoid. The powertrain control module (PCM) commands the solenoid ON or OFF by closing or opening the ground, and monitors voltage levels. When the 2-3 SS valve is commanded ON, the PCM receives low voltage. When the 2-3 SS valve is commanded OFF, the PCM receives high voltage.

DTC P0758 sets if the received voltage is outside the calibration limits, indicating an open or short. DTC P0758 is a type A DTC.

Conditions for Running the DTC

^ System voltage is 10-18 volts.
^ The engine speed is greater than 500 RPM for 5 seconds.
^ Not in fuel shut off.

Conditions for Setting the DTC

DTC P0758 sets if either of the following occurs continuously for 5 seconds:

^ The PCM commands the solenoid ON and the voltage signal to the PCM remains high (B+).
^ The PCM commands the solenoid OFF and the voltage signal to the PCM remains low (0 volts).

Action Taken When the DTC Sets

^ The PCM illuminates the malfunction indicator lamp (MIL).
^ The PCM commands 3rd gear only.
^ The PCM inhibits TCC operation.

Conditions for Clearing the MIL/DTC

^ The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
^ A scan tool clears the DTC from PCM history.
^ The PCM clears the DTC from the PCM history if the vehicle completes 40 consecutive warm-up cycles without an emission related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

Diagnostic Aids

^ Inspect the wiring at the PCM, the transmission connector, 2-3 shift solenoid connector and all other circuit connecting points for the following conditions:
- A backed out terminal
- A damaged terminal
- Reduced terminal tension
- A chafed wire
- A broken wire inside the insulation
- Moisture intrusion
- Corrosion
^ When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.
^ Ensure that the scan tool commanded gear has correct solenoid states and ratio.

Test Description

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

6. This step isolates the fault between the engine harness and the transmission harness.
8. This step checks if the engine harness circuit 1223 is open.
11. This step checks if the solenoid and transmission circuit is within resistance specifications.