Table 1: | Shift Solenoid Valve State and Gear Ratio 4L60-E |
Table 2: | DTC P0751 1-2 Shift Solenoid Valve - Performance |
The 1-2 Shift Solenoid Valve (1-2 SS Valve) controls fluid flow acting on the 1-2 shift valve and the 3-4 shift valve. The 1-2 SS Valve is a normally-open exhaust valve. Used with the 2-3 Shift Solenoid Valve (2-3 SS Valve), the 1-2 SS Valve allows four different shifting combinations.
When the PCM detects a 1-1-4-4 only or a 2-2-3-3 only shift pattern, then DTC P0751 sets. The pattern that the PCM detects depends on the mechanical failure. DTC P0751 is a type B DTC.
• | No TP DTCs P0122 or P0123 |
• | No VSS DTC P0502 |
• | No TCC Stuck ON DTC P0742 |
• | No 1-2 SS Valve DTC P0753 |
• | No 2-3 SS Valve DTC P0758 |
• | No TFP Val Position Sw. DTC P1810 |
• | Previous shift time is greater than 0.0 seconds. |
• | The gear range is D4. |
• | The engine speed is greater than 400 RPM for 8 seconds and not in fuel cutoff. |
• | The vehicle speed is greater than 8 km/h (5 mph). |
• | Transmission temperature is between 20° and 130°C (68° and 266°F). |
• | The traction control is not active. |
All the above conditions have been met and the combination of Conditions 1,2,3, and 4 or 1,2,3, and 5 occurs two consecutive times.
• | Commanded 1-2 shift |
• | The TP angle is 8- 42%. |
• | The TP angle is constant within +/-3%. |
• | Vehicle speed is 8 -64 km/h (5-40 mph). |
• | Within 3.75 seconds, the engine speed in 2nd gear must be 150 RPM greater than the last speed in 1st gear. |
• | Commanded 2-3 shift |
• | The TP angle is 9-32%. |
• | The TP angle is constant within +/-3%. |
• | Vehicle speed is between 32 and 72 km/h (20 and 45 mph). |
• | Within 2.25 seconds, the engine speed in 3rd gear must be 150 RPM less than the last speed in 2nd gear. |
• | Commanded 3-4 shift |
• | The TP angle is 9-27%. |
• | The TP angle is constant within +/-3%. |
• | The vehicle speed is 68-105 km/h (42-65 mph). |
• | Within 3.5 seconds, the engine speed in 3rd gear must be 15 RPM greater than the last speed in 4th gear. |
• | Commanded 4th gear |
• | The TCC is ON. |
• | The TP angle is 9-27%. |
• | The speed ratio is 42-47 (the speed ratio is the engine speed ÷ the output speed). |
• | The TCC slip speed is 500-1000 RPM for 5 seconds. |
• | Commanded 4th gear |
• | The TCC is ON. |
• | The TP is 9-27%. |
• | The Speed ratio is 30-34 (the speed ratio is the engine speed ÷ the output speed). |
• | The TCC slip speed is 20-40 RPM for 5 seconds. |
The PCM illuminates the Malfunction Indicator Lamp (MIL).
• | 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. |
• | Verify that the transmission meets the specifications in the Shift Speed . |
• | More than one shift may occur because of other internal transmission failures. |
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 |
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 verifies that the following sequence occurs:
The scan tool commands all shifts.
All the shift solenoids respond properly.
Not all the shifts occur.
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. Select each transmission range Low, Dr 2, Dr 3, Overdrive, Park, and Reverse. Does each selected transmission range match the TR Switch displayed on the scan tool? | -- | |||||||||
Road testing the vehicle may be necessary. Was a 1-1-4-4 or 2-2-3-3 only shift pattern detected? | -- | Go to Diagnostic Aids | ||||||||
4 |
Did you find and correct a problem? | -- | -- | |||||||
5 |
Has the test run and passed? | -- | System OK |