| Table 1: | Shift Solenoid Valve State and Gear Ratio 4L60-E |
| Table 2: | DTC P0756 2-3 Shift Solenoid Valve - Performance |
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
| • | No TP DTCs P0122 or P0123 |
| • | No VSS DTC P0502 |
| • | No TFT Sensor DTCs P0712 or P0713 |
| • | No TFP Valve Position Switch DTC P1810 |
| • | The vehicle speed is greater than 32 km/h (20 mph). |
| • | The gear range is D4, D3, D2 or D1. |
| • | The engine speed is greater than 400 RPM for 8 seconds and not in fuel cutoff. |
| • | The transmission fluid temperature is greater than 20°C (68°F). |
All of the above conditions are met and either one of the following fail-conditions occurs:
Condition 1
| • | The TP angle is greater than 45%. |
| • | First gear is commanded. |
| • | The speed ratio is less than 115 (speed ratio is engine speed ÷ output speed). |
| • | All conditions are met for 1 second. |
Condition 2
| • | The TP angle is greater than 18%. |
| • | Fourth gear is commanded. |
| • | The speed ratio is greater than 100 (speed ratio is engine speed ÷ output speed). |
| • | 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 6 seconds. |
| • | All conditions are met for 2 seconds. |
Action Taken When the DTC Sets
The PCM illuminates the Malfunction Indicator Lamp (MIL).
Conditions for Clearing the MIL/DTC
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.
Diagnostic Aids
| • | Verify that the transmission meets the specifications in the Shift Speed . |
| • | Other internal transmission failures may cause more than one shift to occur. |
Gear | 1-2 Shift Solenoid | 2-3 Shift Solenoid | Gear Ratio |
|---|---|---|---|
1 | ON | ON | 3.059:1 |
2 | OFF | ON | 1.625:1 |
3 | OFF | OFF | 1.000:1 |
4 | ON | OFF | 0.696:1 |
Test Description
The numbers below refer to the Step numbers on the diagnostic table.
-
This step verifies that the TFP Valve Position Switch is functioning normally.
-
This step tests for a selected gear ratio vs a ratio not obtainable under normal driving conditions.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Powertrain On Board Diagnostic (OBD) System Check , Section 6 | |||||||
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. Does each selected transmission range match the TR Switch on the scan tool? | -- | |||||||||
Road testing the vehicle may be necessary. Was 1st gear commanded and not achieved, or 4th gear commanded and other than 4th gear occurred? | -- | Go to Diagnostic Aids | ||||||||
4 | Check the shift circuit for the following conditions:
Did you find and correct a problem? | -- | -- | |||||||
5 |
Has the test run and passed? | -- | System OK |
