P 1251 Fault Code

[klm7]

I have a 2003 D-4D Avensis 1.9 engine. I'm having problems with the car, the tester showed me an unknown code fault code P 1251. Does any one knows what this code means? Thank you!

[cfc1]

After a google around it seems that code p1251 is a manufacturer specific code, in other words, the same code from a different manufacturer will point to a different problem. In your case (Toyota) the code came up a couple of times as..

P1251 - overboost condition (too high)

.. but most sites don't list p1251 as a Toyota code, the code Toyota seem to use for a boost problem with the turbo is..

P1511 Boost Pressure Low.

P1512 Boost Pressure High.

Is there a chance there was a mix up when you were told the code?.. numbers the wrong way round?

If you car is still under warranty, take it in and get the dealer to check the turbo.

It would also help if you mentioned any symptoms you have been getting.. lack of power etc?

Just in case of a mix up... P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control is a code thats close to what you were told.

[Beagh1958]

To Klm7,

Error code P 1251 is a generic code from canbus protocal. Should register as "Air Mixture Solenoid Circuit Malfunction" am quite sure Toyota may have another name for this device? As suggested by cfc1 best place for your car is nearest Toyota agent & cough up for an hr's diagnostics check.

Regards, Beagh.

PS. Let us know how you get on please.

[Alex-malta]

To Klm7,

Error code P 1251 is a generic code from canbus protocal. Should register as "Air Mixture Solenoid Circuit Malfunction" am quite sure Toyota may have another name for this device? As suggested by cfc1 best place for your car is nearest Toyota agent & cough up for an hr's diagnostics check.

Regards, Beagh.

PS. Let us know how you get on please.

Welcome to the P1251 club!

I get the same code on my rav 4. Appartently they change the turbo which is really costly. I opted not to do it. Been browsing some forums and changing the turbo doesn't necessarily solve the problem...

This is what I have done up to now:

1.Checked EGR valve (very simple put a piece of cloth in the exhaust pipe and put you foot on the pedal to see if the engine stops. If it stops then the egr is messed up)

2. Reconditioned the turbo - (get someone to open it and clean it)

3.check the hot wire sensor on the air flow meter.(clean it with something)

4. Now I am changing the Supply control valves. A mechanic also told me to check the temperature sensor.

will let you know when i solve it -

[klm7]

coming back to you about the fault P 1251.

I have solved the situstion with the P 1251 fault code. I went to the Toyota dealer and they found problems with the vacuum valve, I have change it and everything works well for now!

Thanks a lot for all your posts and help!

[jimmythemarker]

been getting p1251 fault code when a vensis d4d goes into limp mode.my mechanic friendsays its vacuum pipe related ,i just switch off and then start engine again and full power is restored ,hope this helped