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 valves. The 1-2 SS Valve is a normally-open exhaust valve that is used with the 2-3 Shift Solenoid Valve in order to allow four different shifting combinations. The solenoid attaches to the control valve body within the transmission. The 1-2 SS Valve receives ignition voltage through circuit 1020. The Powertrain Control Module (PCM) controls the solenoid by providing the ground path on 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 system voltage is 8-16 volts.

^ The engine speed is greater than 450 RPM for 5 seconds.

^ Not in fuel cutoff.

^ All of the above conditions are met for 5 seconds and either of the following fail conditions occurs for 5 seconds:

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

- The PCM commands the solenoid OFF and the voltage input remains low (0 volts).

ACTION TAKEN WHEN THE DTC SETS

^ The PCM illuminates the Malfunction Indicator Lamp (MIL).

^ The PCM commands D2 line pressure.

^ The PCM inhibits 3-2 downshifts if the vehicle speed is greater than 48 km/h (30 mph).

^ The PCM freezes shifts adapts from being updated.

^ DTC P0753 stores in PCM history.

CONDITIONS FOR CLEARING THE MIL/DTC

^ The PCM turns OFF the MIL after three consecutive trips 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 at the PCM, the transmission connector and all other circuit connecting points 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.

- Moisture intrusion.

- Corrosion.

^ 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.

^ Refer to the 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 Automatic Transmission Wiring Harness Assembly (A/T Wiring Harness Assembly).

5. This step tests for power to the 1-2 SS Valve from the ignition through the fuse.

6. This step tests the ability of the PCM and the wiring to control the ground circuit.

13. This step measures the resistance of the A/T Wiring Harness Assembly and the 1-2 SS Valve.