Speed limiter

[Daveo52]

I have an NP300 it's currently limiter at 75mph. There is no speed limiter module fitted and it doesn't look like it's been done in the ECU. Any I ideas?

 

[tweak'e]

I have an NP300 it's currently limiter at 75mph. There is no speed limiter module fitted and it doesn't look like it's been done in the ECU. Any I ideas?

not on ours. but UK models may be different. its also a kind of odd speed.

what motor do you have?

 

[Daveo52]

I now believe it's probably been done in the BCM but can't seem to find anyone who can get into this.

 

[Old.Tony]

At least in the older cars, the BCM has no responsibility for limiting engine power or vehicle speed. Both are exclusively the domain of the ECU (with information provided by the ABS and automatic transmission). I can't think of a reason why they'd move engine management out of the engine control device, so I doubt you'd need to worry about chasing down the BCM (unless it's an anti-theft mechanism that I haven't heard of, which the BCM most definitely is responsible for).

75mph (120km/h) is an odd limitation for the vehicle. The engine is under a fair load at that speed, so having that as a limit for a possibly damaged engine (we call it "limp home mode" ) is quite extreme. Normally the engine in that mode is limited to 2,000rpm, boost is limited as is fuel rail pressure - and that ends up with a top speed of around 80km/h.

So - I wonder if it's something else, like a fuel or air restriction? Can you hold the vehicle in a lower gear and get full power and RPMs up to 4,000 or does it feel like it's giving up around 3,000rpm?

 

[tweak'e]

without knowing which engine you have (they come out with at least 4) and what the actual problems you have been experiencing, we are barking up the wrong tree.

 

[landmannnn]

It is possible if the D23 is an ex-utility company vehicle that the 75mph limiter has been set into the ECU.

 

[Daveo52]

Hi Guys
firstly it's most definitely a speed limiter not a power issue. Yes it's certainly been put on by a previous company owner, (I've actually unplugged the telematics they'd fitted) 75mph on the speedo is bang on 70mph on the sat nav so there's the reason. Had a guy who does my re-mapping look in the ECU and it's not been touched.

 

[landmannnn]

You just need to find the add on speed limiter module.

They use a GPS receiver which will me mounted under the top of the dashboard, find that first.

 

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could it be a mechanical adjustement, came upon one that i adjusted from a mate who bought ex army vehicle, older car