check engine light came on, hooked up odb2 scanner, came back with this code..(P0751 shift solenoid a ckt performance or stuck off.) looked up the codes and i did not see this one, any and all help would be greatly appreciated. tranny was rebuilt a few months ago.any harm being done here thanks all.

 

Here is some info on it:

DTC P0751 1-2 Shift Solenoid Valve Performance




Circuit Description

The 1-2 Shift Solenoid Valve (1-2 SS Valve) controls the fluid flow acting on
the 1-2 and 3-4 shift valves. The 1-2 SS Valve is a normally-open exhaust valve
that is used with the 2-3 Shift Solenoid Valve (2-3 SS Valve), in order to allow
four different shifting combinations.
When the PCM detects a 1-1-4-4 or a 2-2-3-3 shift pattern, depending on the
state of the mechanical failure, then DTC P0751 sets. DTC P0751 is a type A DTC.


Conditions for Setting the DTC
No TP Sensor DTCs P0122 or P0123.
No VSS Assy. DTCs P0502 or P0503.
No TCC Sol. Valve DTC P0740.
No TCC Stuck ON DTC P0742.
No 1-2 SS Valve DTC P0753.
No 2-3 SS Valve DTC P0758.
No 3-2 SS Valve Assy. DTC P0785.
No TFP Val. Position Sw. DTC P1810.
No TCC PWM Sol. Valve DTC P1860.
The engine speed is greater than 450 RPM for 5 seconds.
Not in fuel cutoff.
The gear range is D4.
The vehicle speed is greater than 8 km/h (5 mph).
The transmission fluid temperature is 20-130°C (68-266°F).
All of the above conditions are met three times and the combination of

Conditions 1,2,3 and 4 or Conditions 1,2,3 and 5 occurs three times.

Condition 1
The PCM commands a 1-2 shift.
The TP angle is 10-40%.
The TP angle is constant within +/- 5%.
The vehicle speed is 8-56 km/h (5-35 mph).
Within 2 seconds, the engine speed in 2nd gear is 100 RPM greater than the
last speed in 1st gear.

Condition 2
The PCM commands a 2-3 shift.
The TP angle is 10-45%.
The TP angle is constant within +/- 7%.
The vehicle speed is 16-80 km/h (10-50 mph).
Within 2 seconds, the engine speed in 3rd gear is 50 RPM less than the last
speed in 2nd gear.

Condition 3
The PCM commands a 3-4 shift.
The TP angle is 8-35%.
The TP angle is constant within +/- 7%.
The vehicle speed is 32-105 km/h (20-65 mph).
Within 2 seconds, the engine speed in 4th gear is 10 RPM greater than the
last speed in 3rd gear.

Condition 4
The PCM commands 4th gear.
The TCC is ON.
The TP angle is 7-35%.
The speed ratio is 0.95-1.20.
The TCC slip speed is 200-1000 RPM for 4 seconds.

Condition 5
The PCM commands 4th gear.
The TCC is ON.
The TP is 7-35%.
The speed ratio is 0.65-0.8.
The TCC slip speed is -20 to +40 RPM for 4 seconds.


Action Taken When the DTC Sets
The PCM illuminates the Malfunction Indicator Lamp (MIL).
The PCM commands D2 line pressure.
The PCM inhibits 3-2 downshifts if the vehicle speed is greater than 48 km/h
(30 mph).
The PCM freezes shift adapts from being updated.
DTC P0751 stores in PCM history.

Conditions for Clearing the MIL/DTC
The PCM turns OFF the MIL after three consecutive trips 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 4L60-E Shift
Speed table.
Other internal transmission failures may cause more than one shift to occur.
Shift Solenoid Valve State and Gear Ratio 4L60-EGear1-2 Shift Solenoid2-3
Shift SolenoidGear Ratio
1ONON3.059:1
2OFFON1.625:1
3OFFOFF1.000:1
4ONOFF0.696:1


Test Description

The numbers below refer to the step numbers on the diagnostic table.
This step tests that the scan tool commanded all shifts and all shift solenoid
valves responded correctly, but all the shifts did not occur.

 

thanks that is some serious info, now is it serious? can you tell by the code how serious the problem is if one exists at all, service engine soon light has been coming on for the last month all the time, my tuner reset and cleared and said everything was o.k, still comes on, i would like to know if i should drive the car to work or not, my daily driver gonna call xtreme in a couple hours, car shifts fine(a4) so i dunno. thanks again,anyone else?

 

[QUOTE=Nukecop]check engine light came on, hooked up odb2 scanner, came back with this code..(P0751 shift solenoid a ckt performance or stuck off.) looked up the codes and i did not see this one, any and all help would be greatly appreciated. tranny was rebuilt a few months ago.any harm being done here thanks all. [/QUOTE

I got this code after I installed my TC (SS36000). I erased the code and reset the check engine light and car ran fine. Happend again about a week later and I again erase the code and later had my tuner turn it off. Car has run fine since then.

 

[
I got this code after I installed my TC (SS36000). I erased the code and reset the check engine light and car ran fine. Happend again about a week later and I again erase the code and later had my tuner turn it off. Car has run fine since then.[/QUOTE]

yes a SS3600 stall was installed when the tranny was rebuilt, HOPEFULLY SAME DEAL, THANKS.

 

This isn't uncommon with larger stalls. If you have 1st and 4th (OD) gears you almost certainly don't have a real issue. If you find that it happens a lot and you don't think you have a mechanical issue, you can have it turned off in your PCM. The issue is that your new converter behaves almost exactly like the trouble this is designed to detect, "insufficient" RPM change after commanded shift. I've seen it maybe a half dozen times in the last three or four years on my car. That's a false alarm rate I can live with.