LIMP MODE BUT NO FAULT CODES

[jelly1703]

Hi all,

Just looking for some advice, I have  a Berlingo 2010 plate 1.6HDI Enterprise Van

I recently purchased it with 44k miles and a good MOT history

Once I started driving it myself, the van started going into Limp mode at random occasions, there's not much a pattern of when it happens, and once i restart the engine, it is fine. No warning lights come up when this happens either so I've took it to two local garages now and when plugged in there are no fault codes appearing at all

One garage suggested to change the fuel filter as they can be a suspect, we did so and it did not resolve the issue. The garage had it back in to what we thought was to do more extensive investigation on the fuel and turbo system but comes to our knowledge all they did was plug it back in and basically didn't want anything to do with it so we've now got it booked in with our local Citroen dealership garage in hopes they have a bit more expertise on the van.

I'm just seeing if anyone has any suggestions to what may be causing this, it normally only happens really when I'm at 50mph + but other than that it's just completely random, the van itself is pretty clean and perfect except this one issue

Thank you in advance 

[cancunia]

Welcome.

As the fault is clearing when you restart, maybe that's why there are no codes, perhaps getting codes read before turning the engine off will help. Can you describe what happens when it goes into 'limp mode'? One way to track what's happening, will be to have a diagnostic trace running while you are driving, the simplest method is with an OBD reader connected to a phone running an app like Torque. If that does not show up any problems, the next step up will be a live trace using the official Diagbox system. The dealership will use Diagbox, but you can also get a system for under £50 so long as you have a laptop.

[jelly1703]

Welcome.

As the fault is clearing when you restart, maybe that's why there are no codes, perhaps getting codes read before turning the engine off will help. Can you describe what happens when it goes into 'limp mode'? One way to track what's happening, will be to have a diagnostic trace running while you are driving, the simplest method is with an OBD reader connected to a phone running an app like Torque. If that does not show up any problems, the next step up will be a live trace using the official Diagbox system. The dealership will use Diagbox, but you can also get a system for under £50 so long as you have a laptop.

Once it goes into limp mode I just can't rev it anything above 2000, and the speed reduces down to 40mph, once i restart it's fine. 

One garage mentioned it could be the turbo pressure and other people recommended putting some good quality diesel in to clean out the system, from the mileage and MOT history it's not driven much, only 6k miles since 2019 so we don't know if some old diesel in the system is causing an issue

 I will speak with my dad in law as he has a OBD reader if his can connect to a phone to do it whilst driving. But I thought when you plug it in, it will see any fault codes that have come up whilst driving

[cancunia]

You're right, normally fault codes are stored but I wondered if they are being cleared on restart somehow as can happen with certain types codes. My 2.0 Berlingo had similar problems which was cured by a new MAF, there was no warning light / EML. I can't remember for sure as it was quite a while ago but IIRC there were no codes after the fault had cleared itself on restart.

[jelly1703]

It does sound similar, and i've read on other forums people who did have similar issues with random occasions of limp mode and gave them EGR fault codes but once they replaced the MAF it resolved the fault

It normally sets off once i rev over 3000rpm, I live in Cornwall so a lot of the major routes are on hills, so to retain speed i rev higher and then it goes limp mode and I have to pull over to restart, but it's just bizarre no engine light comes on either when this happens

luckily its still driveable and i've gotten use to how to drive it to prevent it as much as possible but ideally i don't want to restart the vehicle every journey i take to work in the morning

Hopefully i can get my dad in law to take it out this weekend with his fault reader if it will connect to a phone see if anything comes up. It's not in to the garage until december when i could get a courtesy vehicle so hopefully if investigate a little more myself between then and now, i can give some info to the garage, i'm not sweating as it's got a warranty until march so any major repair costs will be reimbursed to myself

[Pedronicus]

Does the engine light come on briefly and then go out when you start the engine?

[jelly1703]

Yeah so all my dash lights come on as normal before i ignite the engine and then go off once the engine is running

[SteveE]

Might be with checking your Radiator Fan relay..
I had a very similar problem > limp mode that would reset if I switched the engine off then back on. (It seemed to happen when the car got up to or near to normal temperature )
10 minute job to change it but to get at it is a nightmare, I had to take my front bumper off to gain access, then it's just two electrical plug connections and one screw. I couldn't find any fault codes with my cheap reader but my mates 'garage type' reader came up with codes P094 + P095 - 'Radiator fan speed'
Link below to the one I got off eBay - £12.95, cured it.
https://www.ebay.co.uk/itm/114775820945?...Sw6CJbFTdE

[jelly1703]

I got my dad in law to drive it this weekend, he thinks it may have had a speed limiter put onto it at some point with a rev inhibitor. It however doesn't always limit the speed except once you rev it above the 3000rpm

He drove it and it only would go into running flat almost once you hit 3000rpm, but it would gain speed and rev gradually again without having to restart the van

Only a dealership garage will be able to see if there is anything on the ecu controlling the speed or rev

Could this be it? It would explain the no fault codes if its been programmed in ans the fact the van regains speed and throttle even if it is slow to do so

[cancunia]

3000 rpm is the limit mine had when in limp mode, also little or no boost. It would still reach 70 mph eventually. Have you tested the top speed?