Go Back   The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club Forums > Technical Help Forum
Register FAQ Image Gallery Members List Calendar Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 11th March 2022, 21:22   #1
rikk
Avid contributor
 
Rover 75 CDTI

Join Date: Mar 2007
Location: Ashby de la Zouch
Posts: 104
Thanks: 3
Thanked 2 Times in 2 Posts
Default Engine Check Light - pre supply pressure sensor

On my ZT CDTi Auto, a few times recently the "check engine" message has flashed up.. only for a second or so, it's not stayed on.. but has never done this before. I connected it up to "TOAF" and that tells me the error code is "1255 pre-supply pressure sensor".

Just wondering if this is something i need to address urgently.. could the car break down due to this or is it something i don't need to worry about too much? I wasn't sure if i should fit a new sensor, or if it could be due to something else.

The car runs pretty well, though saying that it really doesn't like steep hills!.. really seems to struggle sometimes but i'm not sure if these cars are always like that as it's quite a heavy car and not a massively powerful engine? Or maybe there is something wrong with mine (it does have about 195k on it now, but i have had it serviced properly, injectors reconditioned etc..)
rikk is offline   Reply With Quote
Old 11th March 2022, 21:25   #2
Typhoon190
This is my second home
 
MG ZT-T 190 Monogram Typhoon

Join Date: Jan 2009
Location: Oxfordshire
Posts: 4,704
Thanks: 328
Thanked 557 Times in 443 Posts
Default

I'm afraid I have no real experience of the diesel engine, but could it be one of the fuel pumps wearing out, struggling with delivering the required fuel pressure? Hopefully someone will come along with some more help.
Typhoon190 is offline   Reply With Quote
Old 11th March 2022, 22:01   #3
trikey
Premium Trader
 
trikey's Avatar
 
Rover 75

Join Date: Nov 2010
Location: Devon
Posts: 33,711
Thanks: 8,837
Thanked 14,831 Times in 8,030 Posts
Default

Pull of the electrical connector on the underbonnet diesel filter, make sure the pins are clean then replace it.

Quite a common thing on the diesels for causing the engine light.
__________________
Lest we forget..
trikey is offline   Reply With Quote
Old 12th March 2022, 11:47   #4
rikk
Avid contributor
 
Rover 75 CDTI

Join Date: Mar 2007
Location: Ashby de la Zouch
Posts: 104
Thanks: 3
Thanked 2 Times in 2 Posts
Default

Thanks for the replies, I will check/clean the plug on the sensor in the first instance then. The fuel pumps should be okay as they were both replaced recently.

Is it normal for the cdti auto to lack power going up steep hills though? Mine just doesn't want to pull, and there will be sometimes a violent jerk from the gearbox as it seems to try to change down then immediately back up again. It's ok to maintain speed going up these hills but it won't accelerate..
rikk is offline   Reply With Quote
Old 12th March 2022, 14:27   #5
Yorkshire GOC
I really should get out more.......
 
Yorkshire GOC's Avatar
 
Rover 75 connoisseur se v6 auto

Join Date: May 2014
Location: Hull
Posts: 2,058
Thanks: 1,842
Thanked 623 Times in 469 Posts
Default

Quote:
Originally Posted by rikk View Post
Thanks for the replies, I will check/clean the plug on the sensor in the first instance then. The fuel pumps should be okay as they were both replaced recently.

Is it normal for the cdti auto to lack power going up steep hills though? Mine just doesn't want to pull, and there will be sometimes a violent jerk from the gearbox as it seems to try to change down then immediately back up again. It's ok to maintain speed going up these hills but it won't accelerate..
Struggling up hills in a diesel points in my mind to a fuel injector beginning to fail - i would do a leak back test to confirm or discount that as the cause.
__________________
She came off the Longbridge Line on 20-05-2003

The Silver Machine was the 13th of 160 Rover 75's to come off the production line that day and is the 100th of 527 Starlight Silver Rover 75 2.5 V6 Connoisseur SE Auto saloons listed in the build records produced world wide.
Yorkshire GOC is offline   Reply With Quote
Old 12th March 2022, 14:32   #6
Yorkshire GOC
I really should get out more.......
 
Yorkshire GOC's Avatar
 
Rover 75 connoisseur se v6 auto

Join Date: May 2014
Location: Hull
Posts: 2,058
Thanks: 1,842
Thanked 623 Times in 469 Posts
Default

Quote:
Originally Posted by rikk View Post
Thanks for the replies, I will check/clean the plug on the sensor in the first instance then. The fuel pumps should be okay as they were both replaced recently.

Is it normal for the cdti auto to lack power going up steep hills though? Mine just doesn't want to pull, and there will be sometimes a violent jerk from the gearbox as it seems to try to change down then immediately back up again. It's ok to maintain speed going up these hills but it won't accelerate..
Struggling up hills in a diesel points in my mind to a fuel injector beginning to fail - i would do a leak back test to confirm or discount that as the cause.
__________________
She came off the Longbridge Line on 20-05-2003

The Silver Machine was the 13th of 160 Rover 75's to come off the production line that day and is the 100th of 527 Starlight Silver Rover 75 2.5 V6 Connoisseur SE Auto saloons listed in the build records produced world wide.
Yorkshire GOC is offline   Reply With Quote
Old 13th March 2022, 09:48   #7
Mike Noc
This is my second home
 
Mike Noc's Avatar
 
Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4.

Join Date: Jul 2009
Location: Hampshire
Posts: 11,531
Thanks: 3,470
Thanked 3,119 Times in 2,247 Posts
Default

When was the fuel filter last changed? Might be worth putting a new one in.
Mike Noc is offline   Reply With Quote
Old 13th March 2022, 09:56   #8
Mike Noc
This is my second home
 
Mike Noc's Avatar
 
Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4.

Join Date: Jul 2009
Location: Hampshire
Posts: 11,531
Thanks: 3,470
Thanked 3,119 Times in 2,247 Posts
Default

Quote:
Originally Posted by Yorkshire GOC View Post
Struggling up hills in a diesel points in my mind to a fuel injector beginning to fail - i would do a leak back test to confirm or discount that as the cause.

The engine can go into limp mode with reduced fuel pressure on the low pressure side so I'd look at that first before considering anything on the high pressure side.
If the UBP has been replaced recently then check that the clear plastic inlet pipe cover, if fitted, was removed before fitting the pump, as that will cause exactly the same symptoms if it is wedged in the pipe under the UBP.
Came across this a couple of years ago after the owner had been advised by a BMW garage that he needed to replace the HP pump.
Mike Noc is offline   Reply With Quote
Old 13th March 2022, 10:59   #9
rikk
Avid contributor
 
Rover 75 CDTI

Join Date: Mar 2007
Location: Ashby de la Zouch
Posts: 104
Thanks: 3
Thanked 2 Times in 2 Posts
Default

Thanks for replies - will check those points - although it shouldn't be the injectors - had them recond fairly recently - before that it was struggling to start but now starts very easily, just doesn't seem to have full power when putting my foot right down ..
rikk is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 23:52.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd