P0751

P0751 -1-2 SHIFT SOLENOID VALVE PERFORMANCE - NO FIRST OR FOURTH GEAR (L81)





The 1-2 shift solenoid valve (1-2 SS Valve) is a normally open exhaust valve that in conjunction with the 2-3 shift solenoid valve (2-3 SS Valve), allows four different shifting combinations. The 1-2 SS Valve is attached to the control valve body, within the transaxle. The TCM monitors the actual gear ratio and compares the actual gear ratio with the commanded gear ratio. This diagnostic will detect the following conditions: A stuck Off 1-2 SS Valve, or a stuck Off 1-2 Shift Valve. These conditions will cause the actual gear ratio to be different from the commanded; 2nd gear ratio in 1st and 3rd gear ratio in 4th and thus set DTC P0751.

DTC PARAMETERS
DTC P0751 will set if two occurrences of any of the following cases occur:
1st gear is commanded and the gear ratio is between 1.54 to 1.71 (case 1).

OR

4th gear is commanded and the gear ratio is between 0.91 and 1.07 (case 2) when:
- Engine speed is between 200 RPM and fuel cut-off.
- Tr. Sw. is equal to D4, D3, D2, or D1.
- TP angle is greater than 8%.
- Vehicle speed greater than 8 km/h (5 mph).
- TFT between 21°C (70°F) and 130 ° C (266°F).
- Engine torque is between 35 and 300 Nm (26 and 221 ft. lbs.).
- No ISS, OSS, shift solenoid electrical, TFP, or TP sensor DTCs have been set.
- Ignition voltage is between 8 and 18 volts.

P0751 is a type B DTC

DIAGNOSTIC AIDS
- 1-2 shift solenoid valve - stuck Off.
- 1-2 shift valve - solenoid is leaking - stuck Off.