ST170 IMRC stuck Open

[Minnow]

My ST170's engine management light is permanently on, fault code is P1518, Intake Manifold Runner Control stuck open. According to other forums, this is a fairly common failure usully caused by the plastic control cam on the manifold or fixing pin breaking, leaving the control cable from the IMRC module unattached.

So I checked the control cam on the inlet manifold, cable is still attached, and the IMRC module pulls the cable as it should when the engine is switched on.

I can only assume the IMRC module is incorrectly reporting the fault, but every time I get the fault code re-set, it reappears soon after.

I'm trying to avoid forking out the £200 to replace a unit which appears to be working fine, so does anybody have any ideas what the problem might be or how to get the light to stay off?

[Grayo]

My ST170's engine management light is permanently on, fault code is P1518, Intake Manifold Runner Control stuck open. According to other forums, this is a fairly common failure usully caused by the plastic control cam on the manifold or fixing pin breaking, leaving the control cable from the IMRC module unattached.

So I checked the control cam on the inlet manifold, cable is still attached, and the IMRC module pulls the cable as it should when the engine is switched on.

I can only assume the IMRC module is incorrectly reporting the fault, but every time I get the fault code re-set, it reappears soon after.

I'm trying to avoid forking out the £200 to replace a unit which appears to be working fine, so does anybody have any ideas what the problem might be or how to get the light to stay off?

I seem to have exactly the same problem, except that my very expensive report from the dealer said that code P1518 was the IMRC stuck closed! I've had a poke about and found the IMRC to be working fine - as you described; I can only imagine as you said, that the unit is reporting a non-existent fault.

Your garage were pretty cheap - mine tried to fleece me out of £300 for replacing a unit that doesn't appear to need replacing!

If only someone could help us diagnose the problem! If I find anything out, I'll report back!

[omi77]

Hi,

I've got the same problem, but I don't understand if it is in open state why do I have the same power at low RPM?

The cable is good, the controller moves the cable. It can be a sensor in the module, or something mechanical problem in the inlet manifold. The question is: How does it decide the state of this system (open/close) ? Is it a sensor in the module, or in the manifold?

Omi from Hungary

[footballtaz1]

I have the same problem but mine is stuck open, I have had mine into a ford garage and was quoted £300+ has anyone found a cheaper answer,as this seems to be a common problem. My car is eating petrol could this have something to do with it??? any help

[davedave]

I have the same problem but mine is stuck open, I have had mine into a ford garage and was quoted £300+ has anyone found a cheaper answer,as this seems to be a common problem. My car is eating petrol could this have something to do with it??? any help

Hi i have just had a new IMRC fitted plus manifold kit as it was making a right racket! £200 + £140 fitting! all was good i thought, sounded sweet, management light out, job sorted.....NOT! two hours later the bl@~~#y light come back on??? took it back to fords and they couldn't be more helpful...NOT! they wouldn't even look at it unless i forked out another £70, told them to stuff it! car going well, anybody know how to turn the light out??? :)) cheers.

[craigy]

i used to have a st170 and had same problem i brought part from ford for around 198 and fitted myself which is pretty straight forward after replacing i opened the old one up to find one of the cogs inside had jumped out and got chewed up it seems to me its a bad design cable was fine but after replacing with new one car run alot better i also tried turning light off when this first happened but your find after a while it come back on

[Geek8ter]

I have the same problem on my ST170; the engine management light constantly on, and have been told it is the butterfly valve malfunctioning!! Australian mechanics?! It turns out that the valve is, as the rest of you guys have mentioned, an inlet manifold control which helps the engine produce more torque at lower revs. I have had the car go in to have it tested 4 times and have only been charged for the privilege once buy a pretty good outfit. Thing is, everytime i have the light turned off by the mechanic and his box of tricks, the cars seems to pull a bit smoother and dare i say quicker. So my question is, does anyone else find that their car performs a little better after the light is turned off even if no other work is carried out? I am trying to work out if it is just a software issue of if there is a faulty part. Over here the part is fitted to a fair ammount of the faster Aussie muscle Fords and they charge a !Removed! bomb for them!!

Any advice or suggestions are greatly appreciated, over here they have bumper stickers exclaiming that only milk and juice come in 2 litres. I don't seem to get a great deal of help from the mechanics as they think my car is a waste of space!??!?!?!

[tango667uk]

I too am having the same problem. DTC code P1518 has come on twice, which i have cleared with my code reader. I have checked the plastic 'dsi' clip/lever which the cable from the IMRC connects to and thats still intact.

So... from what i have learned from different forums is that maybe the IMRC control box is knackered, the spring which closes it on the manifold is knackered or the butterfly valves in the manifold itself have given up (hopefully not cos it'll be expensive)

Is there a sensor that reports whether the valve is stuck open or closed on the maifold, or is it part of the IMRC control box reporting on how far the cable is in or out?

[craigy]

I too am having the same problem. DTC code P1518 has come on twice, which i have cleared with my code reader. I have checked the plastic 'dsi' clip/lever which the cable from the IMRC connects to and thats still intact.

So... from what i have learned from different forums is that maybe the IMRC control box is knackered, the spring which closes it on the manifold is knackered or the butterfly valves in the manifold itself have given up (hopefully not cos it'll be expensive)

Is there a sensor that reports whether the valve is stuck open or closed on the maifold, or is it part of the IMRC control box reporting on how far the cable is in or out?

read my post above m8 im sure your find your need to replace box if not sure rip it out and open it up seems to be common problem hth

[ba55man]

hi , someone pls correct me if im wrong , this is how i thought the system worked .

on engine startup and tickover the cable does not pull the lever , i am assuming this is the "closed" position . when the engine revs above 4000rpm the cable then pulls the lever to the "open" position. then below 4000rpm the cable goes slack again allowing the spring to return the lever to the "closed" position

I have the same code fault on my st170

lifted the bonnet started the engine and the cable pulls the lever immediately even at tickover, rev the engine to over 4000rpm but the cable does not go slack to allow the spring to return the lever.

in other words the cable pulls the lever all the time no matter what the engine speed.

Any help would be appreciated