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My car recently started to behave badly. Whwn starting the car I get the following errors on the display. Speed limited mode, ESP fault and engine management fault. I thought it was the MAF sensor and replaced it but the problem persists. I'm now thinking its the MAP sensor and have ordered a new one.

The symptoms are the car would cut out and the errors would be displayed as soo. As the boost started building under hard acceleration. It only ever once displayed a DTC error, P0638, but I cant find any info on it?
I'm going to replace the MAP sensor and see if it will cure the problem.

Mods to my car is a full Milltek system, Radtech intercooler, K&N cais, and custom dreamscience map.
 

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QUOTE(Naranja @ 28 Dec 2009, 02:31 PM) <{POST_SNAPBACK}>I got all those messages when my alternator failed and the battery ran down.

Same with mine after not using the car for a month and then trying to load a map, luckily it was the battery not the alternator.
 

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Problems with the MAP sensor usually manifest themselves with strange Booost,Oil Pressure and Temp readings and locking out 5th and 6th gears! It was a common fault on the late 2007 cars where the MAP sensor plug had come loose!
 

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Discussion Starter · #6 ·
QUOTE(fishface31a @ 28 Dec 2009, 05:10 PM) <{POST_SNAPBACK}>
Problems with the MAP sensor usually manifest themselves with strange Booost,Oil Pressure and Temp readings and locking out 5th and 6th gears! It was a common fault on the late 2007 cars where the MAP sensor plug had come loose!


You may be on to something here. I did get very erratic readings on the temp and fuel readings. I knew my tank was half and all of sudden I had a full tank and the temp was well into the red. Oil temp readings were normal so after restarting the car the erratic readings went away..

My car is a late 2007 model and I did replace all the boost pipes so I had to refit the MAP sensor to the new boost pipe. I'm going to replace the MAP sensor later today and will report back!
 

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QUOTE(spyker @ 29 Dec 2009, 03:40 AM) <{POST_SNAPBACK}>You may be on to something here. I did get very erratic readings on the temp and fuel readings. I knew my tank was half and all of sudden I had a full tank and the temp was well into the red. Oil temp readings were normal so after restarting the car the erratic readings went away..

My car is a late 2007 model and I did replace all the boost pipes so I had to refit the MAP sensor to the new boost pipe. I'm going to replace the MAP sensor later today and will report back!


Another thing that might be worth a look is the plug between the wiring loom and the ECU! It has been known to corrode and give loads of problems although it usually comes up with a CAMBUS fault! The MAP sensor connection itself might also have got a bit of corrosion on it?
 

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Ok, I've found the problem.

I did some research on my errors I kept seeing, P0638 and P2109, and came across the following site.

http://www.bba-reman.com/content.aspx?cont...erTrain_P_Codes

My errors pointed me to a faulty throttle body.

P0638 Throttle Actuator Control Range/Performance (Bank 1)
P2109 Throttle/Pedal Position Sensor A Minimum Stop Performance

Took it off and the butterfly was stuck. It would not move. It felt like something was wedged inside the gears and it would not budge.
Phoned Ford to find out about a new one and was quoted about 700 quid!


So I took it upon myself to dismantle the unit to see what is wrong with it.
All you have to do is pry off the 5 clips holding the black cover in place and carefully lift the cover off, taking care not to damage the little brushes that determine the throttle position. The gears and motor was in perfect condition but the shaft was seized solid.

A little bit of penetrating oil on the shaft next to the butterfly valve and an hour of wriggling it back and forth it eventually freed up. It was now moving smoothly throughout the throttle range. DO NOT put any oil or grease on the gears or inside the casing where the motor is!

So, in the end I saved myself a few hundred quid and learnt something new!


Below are a few photos I took before I reassembled the unit.
 

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Well done at sorting it - yours it not the 1st we have come across with a sticking throttle body.

We have replaced them in the past - never thought of stripping it a cleaning it - again well done
 

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Discussion Starter · #10 ·
I was about too replace it, but after hearing their prices I thought I would give it a go. It's busted in anyway so I can't break it any more can I?
 

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QUOTE(spyker @ 30 Dec 2009, 02:55 PM) <{POST_SNAPBACK}>I was about too replace it, but after hearing their prices I thought I would give it a go. It's busted in anyway so I can't break it any more can I?


Nice one, Glad you saved yourself a few quid.
 

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Never had this problem with fords, but that looks like a bosch unit, done loads of these on VAG and renaults, the audis usually cease and strip the teeth off the cogs.
Well done for sorting it yourself chief.
 
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