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.

When 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 ignition is ON.

^ The system voltage is 10-17 volts.

^ The PCM commands the solenoid ON and the voltage remains high (B+).

^ 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

^ Maximum line pressure

^ The PCM freezes shift adapts from being updated.

^ 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 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 an open condition, massage the wiring harness while watching the test equipment for changes. An open feed circuit can set multiple DTCs.

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 EMI fuse.

15. This Step verifies that the valve's resistance is within specifications.