P0756

Diagnostic Chart:

Performance:

CIRCUIT DESCRIPTION
The 2-3 Shift Solenoid Valve (2.3 SS Valve) controls fluid flow acting on the 2-3 shift valves. The 2-3 SS Valve is a normally-open exhaust valve used with the 1-2 Shift Solenoid Valve (1-2 SS Valve) to allow four different shift combinations.
When the Powertrain Control Module (PCM) detects a non first gear ratio while first gear is commanded or a first gear ratio while fourth gear is commanded, then DTC P0756 sets. DTC P0756 is a type A DTC.

CONDITIONS FOR SETTING THE DTC
^ No engine speed DTC P0219.
^ No Output Speed Shaft (OSS) Sensor DTCs P0722 or P0723.
^ No Transmission Fluid Temperature (TFT) Sensor DTCs P0712 or P0713.
^ No TFP Val. Position Sw. DTC P1810.
^ No shift solenoid electrical DTCs P0753 or P0758.
^ No Automatic Transmission Input Speed Shaft (A/T ISS) Sensor DTCs P0716 or P0717.
^ The engine is running.
^ The vehicle speed is greater than 6 km/h (4 mph).
^ The throttle position is greater than 12%.
^ The transmission fluid temperature is 20-130°C (68-266°F).
^ The engine torque is 100-565 N.m (80-450 lb. ft).
^ The engine speed is 475-3750 RPM for at least 7 seconds.
^ All of the above conditions are met and either of the two following conditions occur:
- When the 2-3 SS Valve is stuck on, the commanded gear equals 1st and the ratio equals 4th for greater than 2 seconds, and the commanded gear equals 2nd and the ratio equals 3rd for greater than 2 seconds. The conditions occur for 2 occurrences.
- When the 2-3 SS Valve is stuck off, the commanded gear equals 3rd and the ratio equals 2nd for greater than 3 seconds. The condition occurs for 7 occurrences with a continual rolling counter.

ACTION TAKEN WHEN THE DTC SETS
^ The transmission immediately lands to 2nd gear.
^ The PCM commands maximum line pressure.
^ The PCM freezes shift adapts.
^ The PCM illuminates the Malfunction Indicator Lamp (MIL).

CONDITIONS FOR CLEARING THE MIL/DTC
1. 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.
2. 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 Shift Speed table.
^ Other internal transmission failures may cause more than one shift to occur.
^ The customer may complain of an engine over-rev condition or neutral condition in 4th gear.
^ First diagnose and clear any engine DTCs that are present. Then inspect for any transmission DTCs that may have reset.
^ Refer to Shift Solenoid Valve State and Gear Ratio table. Shift Solenoid Valve State and Gear Ratio

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step tests the function of the TFP Val. Position Sw.
3. This step tests for a selected gear ratio versus a ratio not obtainable under normal driving conditions.