Help!! - Advice Needed, Possible Pcm Replacement

[Quball42]

Looking for a bit of advice here please guys before I possibly have to spend mega cash on my new CMAX.

Background:

Bought a 2004 CMAX 1.8 Zetec (Petrol) a short while ago with 68k on the clock.

I've started to notice that its hesitating sometimes when I put my foot down and that the rev's sometimes "stick" high when idling then return to normal. MPG has also been a bit lower than I would have expected, around 30mpg, on the couple of motorway runs that I've completed so far. No warning lights or anything on the dash to indicate any issues.

Took it into the local Ford dealers and had a Major service (plugs, filters etc) and it seemed to improve things a little but not completely. I've replaced all the coil packs thinking that it might be one of them breaking down but, again no luck solving the hesitation.

Anyway long and the short of it is I took it into the dealers this morning for them to have a look at it thinking it might be the Throttle body needing a clean etc and have been told that it needs a new PCM - £1400s worth of work

I really need some advice as to if there is anything else that could cause a fault code P0603 - PCM KAM error and what the hell it actually means as the guy on the service front desk didn't really know himself. What does the KAM memory actually store and if I have to drive the car for a month before getting it fixed is it going to cause more expensive issues.

The copy of the diagnostics sheet that I have says the following:

================================================================

Description - P0603

PCM KAM error

Major memory corruption.

No more KAM data can be saved at key OFF or restored at key ON.

This DTC may be caused by :

Faulty or Damaged PCM.

=================================================================

If I have to pay out the £1400 then so be it BUT I really want to make sure that its 100% required before parting with that much hard earned cash. The annoying thing is that so far the car actually drives pretty well apart from this occasional hesitation and the low MPG.

[georgen]

found this,

P0603 Error Description

Powertrain Control Module KAM Test Error Indicates the PCM has experienced an internal memory fault. However there are external items that can cause this DTC. Reprogramming battery terminal corrosion KAPWR to PCM interrupt/open Loose battery connection Damaged PCM If KAPWR is interrupted to the PCM because of a battery or PCM disconnect, DTC can be generated on the first power-up.

[jeebowhite]

good find George!

Paul, start with that and check the earth points and Terminals. I would also suggest that the PCM may be sourced from a scrapyard for a lot less, and with a very minute chance of having an error!

[Quball42]

good find George!

Paul, start with that and check the earth points and Terminals. I would also suggest that the PCM may be sourced from a scrapyard for a lot less, and with a very minute chance of having an error!

Thanks George.

I've been working through the battery connectors etc this afternoon and everything externally seems ok so far. I was thinking the same regarding getting a PCM second hand but from a little digging it seems that the config/software that is on the fitted one has to be re-installed on the new one. Apparently they are almost coded to the car (not exactly but you know what I mean).

Will have to check the connectors to the PCM tomorrow and see what happens from there. Its annoying as well as the code reader I have doesn't show any codes stored at all. So I dont know if either the code is no longer there, cleared by the garage or the actual suspected fault is stopping my reader from seeing it.....

The joys of new cars, give me my old MK2 escort anyday :P

[georgen]

To be honest does it bug you enough to spend £1400, if it did I would sell it. on the replacement old verses new, a new one would need coding to car so they could code a used one in the same way surely.

[wase16ll]

tbh, garage is really jumping the gun by condemning the pcm

this could just as easily be interference in the wiring, no guarantee whatsoever that changing the pcm will rid it of this code.

KAM is what the pcm uses to fine tune the car to your driving style, without KAM, it would be like fitting a whole new PCM every time you start the car, it has to relearn... so its quite plausible this code is active and causing your problem

as an example, interference in wiring could be the known problem of the ht leads shorting across to the cyl head temp sensor...definitley worth checking this

before you do anything, i would clear the code just to see if it returns, as it maybe a non-active code {disconnecting the battery is one way of seeing this code flag up)

if the code does show up as an active one, would seriously be reluctant to just throw a PCM on, this code can be a very tricky problem to find...would start by doing a long hard, visual check of all the wiring, if nothing shows, next step would be send the PCM to specialist for testing....throwing a PCM on in hope is a very expensive gamble