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"Check Engine" light on after service interval reset

8K views 10 replies 3 participants last post by  Tony1 
#1 ·
I bought my Rover 75 2.0 CDTi Connoisseur SE Auto, registered Sept 2004, a few months ago, 26k miles on clock. I had run it around 2000 miles and realised it was overdue its oil service. I found an independent local mechanic who had an exceedingly high rating on our local and very useful "Checkatrade" web site. He seemed (and still does seem) very genuine. He changed the oil and oil filter, but had trouble resetting the service interval. He showed me how he was trying to do it the official way, using a hand-held plug-in instrument, and though it said it was communicating, when it came to finally selecting "reset service interval" it always said it failed.. So he finally did it by using a piece of wire, saying that this wasn't the official method, but worked - and it did. I set off the same day on a longish journey and after about 45 miles I found the car was losing power.. I was in the middle lane of a motorway with lorries inside me, and found I couldn't accelerate.. Worrying.. and very odd, because I'd not had any problems with the car at all since I bought it. I tried changing down, with limited response.. until finally it seemed to recover and, relieved, I completed my journey. The next day on my way back, the "Check Engine" warning light came on.. The next day it started stalling when stopped in traffic (it is an auto).. and the car just felt like it wasn't running smoothly.. lumpy..
The mechanic returned and tried to diagnose the problem, but again, although his instrument detected the car and offered the menu choices, it failed to diagnose, which the mechanic said was unusual. So he took the car off to a garage he knew that had a different brand instrument, and that worked: the print out said :
X431 DIAG Report LAUNCH
SMARTBOX: 980241944400 DATE: 7/12/2006 4:02:36 PM
Total codes: 003
CODE001: Pre-fuel pressure control
CODE002: Cooling fan
CODE003: Air flow meter
Name: J&P
He'd reset the warning light, and had driven it back from this garage (about 4 miles) and said all seemed well. The next day I drove again, and immediately the car started stalling.. and later on the journey the "Check Engine" warning light came on again.. Oddly, the stalling occurred less often now, though the car still ran rather roughly. He is now suggesting that one or more of the diagnosed problems (above) must be genuine, and will order an Air Flow Meter - in his opinion the most likely culprit.
I am concerned that maybe we'll try all of them and nothing will change.. that maybe its the Engine Management System itself that's been damaged - by the shorting out of the service indicator. I did have a similar case with my last car, an old BMW 320 coupe, when after a service indicator reset (again when the garage had had a problem resetting it), the whole instrument panel failed about 15 miles later.. an expensive replacement. Maybe because of that experience I'm being a bit paranoid..
I'd be very grateful for another opinion before I/he (its up for debate.., but I suspect I) starts to pay for various parts that may not solve the problem. After all, why should 3 parts all fail like this.. And he thinks the Cooling Fan is fine, as I do - certainly it seems to operate ok.
Anyone help..?
Thanks...
 
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#2 ·
Welcome, good post!

resetting the service indicator is easy even with a bit of wire I would be surprised if his hand held has damaged anything.

It look like you have three faults

If your AC (rad fan behind the grill) comes on at hovercraft speed when you switch on the AC then that will do for now concentrate on getting the engine working properly

The Maf is easy don't bother getting a replacement yet we have a member here who can offer you a far better set of alternatives

To proove if the Maf is causing you low power and stalling issue is easy unplug it and drive the car it will do absolutely no harm and if the car goes like it never has for ages then you maf is stuffed

AC fans grrrrrrrrrrrrrrr.............. read my various post here all about it :)
it is has probably lost one or more of its three speeds.

pre fuel pressure control, pass, that might be the low pressure sensor which might mean you have an iffy pump but don't worry about those yet, a trip to a proper mgr dealer might be needed to verify what it is as that is the only one of the three that might cause the light to come on.

Start with unplugging the maf as that is a good test, but the MAF itself will not cause the warning light to come on so you probably do have something else wrong

Your car engine management system is Rover specific most third party diagnostics heads can not read the codes properly so will not be 100% accurate
 
#3 ·
It may also be the low pressure pumps playing up as usual, causing the pressure to drop and insufficient to supply the injection pump.

The cooling fan code is probably wrong..

My ACR4 comes up with this message and also "cruise control signal line" (no CC fitted!) after I have unplugged the maf sensor.

So it should be reporting something like "maf signal to low" and "egr flow insufficient" due to the unplugged maf sensor.

Neither will cause the check engine light.

However the lp fuel code will cause the check engine light to come on (if you unplug the lp pressure sensor it will come on as well)

So I would suggest everything points to the low pressure pumps.

Do you remember how much fuel was in the tank - i.e. had you let the tank drop below 1/4 full when the problems started?

To confirm if it is a pump issue, drive with the tank well above 1/2 full for a few days and see if the problem recurrs.

If not, its the pumps.

Ron
 
#4 ·
Many thanks Keith & Rover_ron, much appreciated.
Yes Ron, the fuel tank was below 1/4 full at the time of the first symptoms - the lack of acceleration on the motorway. On the 2nd day return journey, the fuel low lamp and the engine check light had both come on before I finally filled up. Once filled up the engine had run fine for the rest of that day, about 100 miles. The next (3rd) day was the one on which the car started stalling and running roughly. It's still well over half full - I've only done about 200 miles since filling - and the rough running & intermittent engine stalling when stopped have continued. So does that mean its not the pump?
However, its interesting that the only one of the 3 reported error codes that would turn on the "Check Engine" warning light is the Pre-fuel pressure control.. If the Engine Management System is indeed undamaged and working, surely this means that the "Pre-fuel pressure control" is definitely in need of attention..?
I will show your valuable input to my mechanic - in the hope that he's not yet purchased the Air Flow Meter. Hopefully he'll disconnect it first as Keith suggested.
I will keep this thread informed as to progress.. Any further ideas would be much appreciated..
 
#5 ·
Tony1 said:
Many thanks Keith & Rover_ron, much appreciated.
Yes Ron, the fuel tank was below 1/4 full at the time of the first symptoms - the lack of acceleration on the motorway. On the 2nd day return journey, the fuel low lamp and the engine check light had both come on before I finally filled up. Once filled up the engine had run fine for the rest of that day, about 100 miles. The next (3rd) day was the one on which the car started stalling and running roughly. It's still well over half full - I've only done about 200 miles since filling - and the rough running & intermittent engine stalling when stopped have continued. So does that mean its not the pump?
However, its interesting that the only one of the 3 reported error codes that would turn on the "Check Engine" warning light is the Pre-fuel pressure control.. If the Engine Management System is indeed undamaged and working, surely this means that the "Pre-fuel pressure control" is definitely in need of attention..?
I will show your valuable input to my mechanic - in the hope that he's not yet purchased the Air Flow Meter. Hopefully he'll disconnect it first as Keith suggested.
I will keep this thread informed as to progress.. Any further ideas would be much appreciated..
If either of both of the pumps are very poorly, you could still get the running / stalling problems regardless of the fuel level. So don't dismiss the pumps as culprits just because the fault occurs with a reasonably high fuel level.

It could also be a clogged fuel filter, or loose fuel pipe on the under bonnet pump.

Ron
 
#6 ·
Many thanks Ron, much appreciated. Have read some of your web site - very good.. Good to know there are some real experts out there and being so helpful to others..
My mechanic hasn't got back to me yet. He was getting married on Saturday so I think he deserves a little space!
I'll keep you informed..
Tony
 
#7 ·
Latest: Mechanic came back & had decided it was the air flow meter, in spite of my having let him know about the advice I'd been given in this forum.. He'd ordered one, fitted it, took it for a test drive & returned to say that it seemed to have cured the stalling, but now the car had no acceleration until it had reached 2-3k revs.. & that therefore the new air flow meter was obviously not right either.. & made calls to his source to ask if this was the right part.. I reminded him that I'd been told that disconnecting it would do no harm & would at least eliminate the problem.. So he did that, & reported that the car then ran fine.. He also noticed that the air filter attached to it was very dirty & questioned whether the filter had been changed as it should have been on its first service at c15k miles - which had a stamp in the service book from a garage in Hendon. He also insisted that the engine warning light would come on if the air flow meter was faulty.. He ran out of time & put the original air flow meter back. The car is now, unsurprisingly, running as before, stalling, rough running..
I now have been told by a friend driving behind me that there is a lot of black smoke coming out of my exhaust, especially when I start off, & intermittently when driving, possibly when I push the throttle some. I am worried that, since my mechanic cannot come again until at least next week, & I have a 250 mile journey this coming weekend, that I could be doing the engine damage by running it in this condition..?
I would be very grateful for any further advice..
Tony
 
#8 ·
Your maf has failed completely.
The staling is due to massive overfuelling, as is the black smoke. (It is outputting far too high a signal.)

Why not just fit a Pierburgh maf from Eurocarparts (£65) and one of my mafam MF75ps? Total cost is about £120. Compared to about £200 for the Rover one, which may not last much more than 30-40kmiles.

In the meanwhile, leave it unplugged - the warning light does NOT come on and this is preferable than the gross overfuelling with the faulty one connected.

Ron
 
#9 ·
Thank you.. Rover_ron, and Keith Alexander earlier. You have been so helpful, and much appreciated. My mechanic, who's had the ultimate excuse to have been absent (his wedding & then his mother passing away the next day), eventually now has replaced the MAF with a standard Bosch (Rover) part, though hasn't yet given me the bill. He did rather force the issue by ordering the part without taking any notice of my messages re. Rover_rons's advice re. the Pierburgh maf and the mafam.. but I am just so relieved that he finally found the time to do it, and that the engine is running smoothly again. I've done about 200 miles since, and so far, so good..

Whether now the other 2 items that the Smartbox diagnostic came up with (see 14/7) are relevant I don't know.. Is it reasonable to assume that if the MAF seems to have solved the problem, the other 2 items were false? I'll let this forum know if anything changes.

Best wishes to all on here who help and advise.

Tony
 
#10 ·
Since your post I have been investigating Diag systems for Rovers the system used o your car is a generic Chineese bit of Kit called the X431 made by a company called Launch.

It does not suport MGR vehicles very well

For accurate diagnosis of the fault codes you need to go to a proper MGR dealer or X Part service centre equipped with the proper MGR diagnostics called Testbook
 
#11 ·
Thanks Keith

The "Launch" kit did at least diagnose (unlike my mechanic's plug-in gizmo). Whether its accurate and the "Pre-fuel pressure control" and the Cooling fan it diagnosed 14/7 will also prove to be problems I'll have to wait and see I guess.. The engine check light hasn't reappeared yet at least. Maybe next time I'll take it to SMC in Hayes - I imagine they should have the Testbook kit?

Any recommendations from anyone as to good garages in my area (Kew/Richmond, Surrey) to maintain my Rover 75 would be appreciated.

Best wishes

Tony
 
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