P0756

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The 2-3 Shift Solenoid Valve (2-3 SS Valve) controls the fluid flow acting on the 2-3 shift valves. The solenoid is a normally-open exhaust valve. The combination of the 2-3 SS Valve and the 1-2 Shift Solenoid Valve allows four different shift combinations.

When the PCM detects a 1-2-2-1 only shift pattern or a 4-3-3-4 only shift pattern depending on the mechanical failure, then DTC P0756 sets. DTC P0756 is a type B DTC.

CONDITIONS FOR SETTING THE DTC

Failure Criteria

^ No TP DTCs P0122 or P0123

^ No Vehicle Speed Sensor (VSS) DTC P0502

^ No Transmission Fluid Temperature(TFT) Sensor DTCs P0712 or P0713

^ No TCC Stuck ON DTC P0742

^ No 2-3 SS Valve DTC P0758

^ No 1-2 SS Valve DTC P0753.

^ No 3-2 SS Valve Assembly DTC P1886.

^ No TCC PWM So. DTC P1860

^ No TCC So. DTC P1864.

^ No TFP Valve Position Switch DTC P1810

^ The vehicle speed is greater than 24 km/h (15 mph).

^ The gear range is 1/4.

^ The engine vacuum is between 20 and 99 kPa.

^ The engine speed is greater than 450 RPM for 2 seconds and less than 5500 RPM.

^ The transmission fluid temperature is between 20 and 130°C (68 and 266°F).

^ The TCC is OFF.

^ All of the above conditions are met and either one of the following fail-conditions occurs:

- The solenoid is stuck ON and Conditions 2 and 3 occur two consecutive times.

- The solenoid is stuck OFF and Conditions 1 and 3 occur two consecutive times.

Condition 1

^ The TP angle is greater than 38 %.

^ First gear is commanded for 2.5 seconds.

^ The speed ratio is between 0.5 and 2.59 (speed ratio is engine speed output speed).

^ The transmission output speed is between 600 and 1500 RPM.

^ The TCC slip speed is between -93 and -2000 RPM for 1.6 seconds.

Condition 2

^ The TP angle is between 13 and 55 %.

^ The TP angle is within +1-3 %.

^ Third gear is commanded for 1 second.

^ Third gear speed ratio is greater than the last 2nd gear speed ratio minus 0.2.

^ Third gear TCC slip speed is greater than or equal to the last 2nd gear TCC slip speed plus 200 RPM for 1.3 seconds.

^ Discontinue the test if the time since shift commanded is greater than 5 seconds.

Condition 3

^ TP angle is greater than 18 %.

^ Fourth gear is commanded for 1 second.

^ Speed ratio is between 2.05 and 8.0 (speed ratio is engine speed output speed).

^ Transmission output speed is 0-8191 RPM.

^ TCC slip speed is 1000-4000 RPM for 3 second.

ACTION TAKEN WHEN THE DTC SETS

^ The PCM commands 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

^ Verify that the transmission meets the specifications in the 4L60E shift speed chart.

^ Other internal transmission failures may cause more than one shift to occur.

TEST DESCRIPTION

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

2. This Step verifies that the TFP Valve Position Switch is functioning normally.

3. This Step tests for a selected gear ratio vs a ratio not obtainable under normal driving conditions.