P0753

Diagnostic Chart:

Wiring Diagram:

Circuit Description

The 1-2 Shift Solenoid Valve (1-2 SS Valve) controls the fluid flow acting on the 1-2 and 3-4 shift valve. The solenoid is a normally-open exhaust valve. The combination of the 2-3 Shift Solenoid Valve and the 1-2 SS Valve allows four different shifting combinations. The solenoid attaches to the control valve body within the transmission. Circuit 439 supplies ignition voltage directly to the 1-2 SS Valve. The PCM controls the solenoid by providing a ground path through circuit 1222.

If the PCM detects a continuous open or a 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 engine speed is greater than 400 RPM for 5 seconds and not in fuel cut off.
- The system voltage is 10-16 volts.
- The PCM commands the solenoid ON and the voltage remains high (Battery Voltage).
- The PCM commands the solenoid OFF and the voltage remains low (0 volts).
- All conditions met for 5 seconds

Action Taken When the DTC Sets
- The PCM commands D2 line pressure.
- The PCM freezes shift adapts from being updated.
- The PCM inhibits downshifts to 2nd when the speed is greater than 30 mph.
- The PCM illuminates the Malfunction Indicator Lamp (MIL).

Conditions for Clearing the MIL/DTC
- The PCM turns OFF the MIL after three consecutive ignition cycles without a failure reported.
- 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 any poor electrical connections at the PCM. Inspect the wiring at the TCC brake switch. Look for the following problems:
- 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 an open, massage the wiring harness while watching the test equipment for changes.
- An open feed circuit can set multiple DTCs.
- Refer to Shift Solenoid Valve State and Gear Ratio.

Test Description

The numbers below refer to the step numbers on the diagnostic chart.
4. This step verifies that the 1-2 SS Valve and the Automatic Transmission wiring harness are functioning normally.
6. This step verifies that the ignition supplies power to the 1-2 SS Valve through the PCM IGN fuse.
16. This step verifies that the valve's resistance is within specifications.