P0753

Diagnostic Chart:

Diagnostic Chart (cont'd):

Wiring Diagram:

Circuit Description
The 1-2 Shift Solenoid Valve (1-2 SS Valve) controls the fluid flow action on the 1-2 and the 3-4 shift valves. The 1-2 SS Valve is a normally-open exhaust valve that is used with the 2-3 shift solenoid Valve (2-3 SS Valve) to allow four different shifting combinations. The 1-2 SS Valve attaches to the control valve body within the transmission. The ignition voltage goes directly to the 1-2 SS Valve. The PCM controls the 1-2 SS valve by providing the ground path through circuit 1222. When the PCM detects a continuous open or short to ground in the 1-2 SS Valve circuit or the 1-2 SS Valve, then DTC P0753 sets. DTC P0753 is a type A DTC.

Conditions for Setting the DTC

^ The ignition is ON.
^ The engine runs for greater than 5 seconds.
^ Invalid output state.
^ A fault is detected for 4.3 out of 5 seconds.

Action Taken When the DTC Sets

^ The PCM commands maximum line pressure.
^ The PCM freezes shift adapts.
^ The PCM illuminates the Malfunction Indicator Lamp (MIL).

Conditions for Clearing the DTC

^ A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.
^ 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 for poor electrical connections at the PCM 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.
^ An open ignition feed circuit can cause multiple DTCs to set.
^ First diagnose and clear any engine DTCs or Accelerator Pedal Position (APP) 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 1-2 SS Valve and the internal wiring harness.
5. This step tests the power to the 1-2 SS Valve from the ignition through the fuse.
7. This step tests circuit 1222 for an open.
8. This step tests circuit 1222 for a short to ground.