Diesel TS2 2005 - Mazda 6 -Limp Mode at idle constantly

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Tue 3 Aug 2010 23:50
Diesel TS2 2005 - Mazda 6 -Limp Mode at idle constantly - deebay

Would be very grateful for an help or info into a problem that has persisted for the last year or more and cannot be solved.

Mazda 6 diesel, common rail, no dpf.
Car will start up, no lights and runs for about 30 seconds at idle, then it will suddenly throw itself into limp mode, running very roughly with the EML illuminated. Light can be put off with scanner, but will do the same thing again almost imediately.

However once the car is driven down the road a bit, constantly reseting the EML, it may then drive for up to 40 miles with no problems or check lights, as long as the car is driven and not sitting at traffic.etc.

Once again after sitting at idle for a short time, the car wil snap into limp mode and won't rev up over 2000rpm. Code is P0627-Fuel pump control circuit A Malfunction.

I know of common problems with pumps and SCVs and injectors. All have been replaced with no change. Even put old parts on another mazda 6 and it ran fine.

Does anybody know of anything that could be causing this to happen? Any suggestions would be gratefully accepted because I'm at my wits end looking at it!

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Wed 4 Aug 2010 09:34
Diesel TS2 2005 - Mazda 6 -Limp Mode at idle constantly - Collos25
Turbo,turbo actuator,egr,maf,ecu,glow plugs how many more do want.
You have not obviously taken it to a proper garage for repair replacing costly items ad lib can prove a little expensive.
I would go for the turbo or turbo accuator after I had proved the maf and the EGR were ok and would clean both while I was at it.
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Wed 4 Aug 2010 12:18
Diesel TS2 2005 - Mazda 6 -Limp Mode at idle constantly - deebay

Haha...proper garage...where would I find one of them?

In fact it has been at 2 Mazda dealers and they have had no idea what is going on. Now at a well respected Independant garage.

What is your reason for suspecting Turbo, or turbo actuator? I cannot see how this could ever cause this symptom. Anyway the Turbo, Egr and MAF are all known good. Independant suspects a wiring fault in harness along front of car. Has been much more helpful than the dealership.;

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Wed 4 Aug 2010 13:17
Diesel TS2 2005 - Mazda 6 -Limp Mode at idle constantly - Collos25

The actuators go faulty and give the symptoms you describe a well documented problem on Mazda and Ford,so does the EGR and so does a coked up turbo and so does a faulty Maf.A diesel injector specialist would be able to check all these parts out correctly.The fault code you are getting is safegaurd of the pump when it goes into limp home mode it could also be historic..I would be suprised if it was faulty wiring as the problem would be constant.They go into limp home mode when one of the steps on the ladder sequence cannot me met in the ECU it is something not opening fully not reaching or exceeding its temperature or not closing fully hence the EGR,turbo actuator or turbo all linked .

Hope the garage finds the problem it can be so frustrating.

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Wed 1 Sep 2010 13:24
Diesel TS2 2005 - Mazda 6 -Limp Mode at idle constantly - deebay

Problem found.

Faulty ECU.
ECU was tested before and they said it was ok.
took it out again anyway and replaced it with 1 from another car (immobiliser aswell), and the car now runs fine.

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