Nanocom not reading boost

Just wondering where does the nanocom get its boost pressure signal from? Mine has stopped reading it and just showing zero even though it's boosting fine on my mechanical gauge.

Wondering which pin on the ecu does it get an output from or maybe I've a MAP sensor that's on the way out which might be why I'm going into limp mode nearly with any sort of decent load on the engine now from thinking it's over boosting too?

When you say it is not reading boost.

Do you mean both the MAP sensor reading and the turbo pressure reading both show ZERO?? If yes, then I would hazard a guess your MAP sensor is fubarred.

Did someone on here not publish a way to check it to see if it was reading correctly at ambient pressure?

Pin numbers and what they do, I think are available amongst the myriad of info available from the website as downloads.

Cheers

DaveM-sport said:

Just wondering where does the nanocom get its boost pressure signal from? Mine has stopped reading it and just showing zero even though it's boosting fine on my mechanical gauge.

Wondering which pin on the ecu does it get an output from or maybe I've a MAP sensor that's on the way out which might be why I'm going into limp mode nearly with any sort of decent load on the engine now from thinking it's over boosting too?

Click to expand...

the map sensor does 2 things ..it monitors boost level and also manifold temp

Ambient pressure is reading about 100 at idle regardless of map sensor connected or not.

Mihht try swapping the map sensor for another one I have from other engines and see if any change

Ambient pressure is a different sensor to the MAP pressure sensor.

100 give or take a few on the AAP is a normal reading for this. disconnecting the MAP should not make any difference to it.

Cheers

Yep, was thinking as much but wasn't sure where it got the reading. Obviously, it gets ambient pressure from the small sensor from the airbox... Was half asleep this morning and now that I think of it, if it got a reading from inside the manifold, it wouldn't be ambient pressure as it'll already be gone through the turbo

Changed map sensor and still the same.

Also getting a Driver Demand Problem 1 which would suggest something up with the pedal maybe. Accelerator tracks are all showing fine at around .7, 4.2 and 4.6 volts though

1. the driver demand code comes back immediately after it was cleared?
2. might be a wiring issue between the ECU and MAP sensor, do you get at least correct inlet air temp reading? a continuity check would be good on that circuit, the MAP input is between pin 6 of ECU red plug hardwired to sensor on that white/yellow wire, check with multimeter see pin disposals

Solved


When doing some other wiring for my new gauges and lightbars and things, I completely removed the old boost box I had still connected up to the ecu, just earth disconnected as I didn't need it with the new ecu map from Alive.

Just thought of it yesterday might I have forgot to plug it back in or maybe a bad connection. It was plugged in alright but the terminal in the plug was slipping back as it was plugged in to the ecu pins.

Reconnected it and made sure the terminal was properly connected and had boost back again and limp mode issue solved.

In addition to that, the overboost issue I previously was also having under full load at higher revs showed up clearer too as Alive reset the limit to 1.6 bar.

It was only ever going to 1.4 on the nanocom (didn't have the Vdo boost gauge previously) but now when properly connected and boost box gone completely, it goes to 1.58bar before it cuts so just a simple issue of adjusting the wastegate