Just got an 87 Aerostar 3.0 L / auto transmission, for free.
Read the codes and got a 52 on KOEO. Both Haynes and Chilton
don't have this code, but tester book states that it is a
" power steering pressure switch open " fault for trucks.
Anyone know what this means in real terms?
Previous owner used Type F tranny fluid instead of Mercon, how
bad is this. Should it be drained and changed?
It may not mean anything. If you didn't turn the wheel at the proper time,
the computer may just not have received the proper input from the pressure
switch. However, it sounds more like you have a bad power steering pressure
switch, or the wiring to it is damaged. I know they exist, and I think
they're in the PS pump housing somewhere. I've never actually changed one
tho. The purpose of the switch is to tell the computer to increase the idle
speed when you're turning the wheel to prevent the extra load from killing
They are prone to leakage and easy to change.. look for a tee with a
switch in the pressure line.
If the switch isnt there, it may have a plug in there. The purpose is to
anticipate additional load and increase engine rpm; thus the IAC doesnt
have to 'work so hard'.. which COULD result in 'hunting'
I would drain and change it, unless it has tens of thousands miles using
type F. In which case, continue it. Who knows what effect changing it
might have on seals if you mixed, again.
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!
Thank you, and everyone else for the help. Found the switch and will
replace if it causes a problem. The tranny leaks a bit of fluid now and
I will probably drive it this way untill the summer, when I will
If you didn't turn the steering wheel during the engine running test, the code
will set. If the switch is actually bad, you may not even notice. Look on the
pressure power steering line, It should be screwed into a fitting on the line. 2
connector and IIRC, the top of the switch is green.
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