ECM tube

[LTB]

I have a 955i -01
On the right hand side of the ECM there is a stiff tube going to the front of the bike.
What is it used for ? What would happen if there is a leak ?
The connection was a bit loose and i taped them together.  

/Thomas

[iansoady]

It sounds like the connector for the atmospheric pressure sensor in the ECU. It plugs into the airbox and allows the ECU to compensate for high altitude etc.

[Bixxer Bob]

It sounds like the connector for the atmospheric pressure sensor in the ECU. It plugs into the airbox and allows the ECU to compensate for high altitude etc.

.

Agreed.  If there's any leaks, your ECM will have the fueling all over the place  ergo, if it's running ok, it's not leaking (although if it's running rough, it's not necessarily a leak, could be loads of other stuff).

[iansoady]

I wouldn't have thought leaks would make any difference as it's only measuring ambient air pressure.

[Bixxer Bob]

I wouldn't have thought leaks would make any difference as it's only measuring ambient air pressure.

.... on the throttle body side of the paper filter, where the bodies are sucking hard.  Triumph manual quote " The barometric pressure sensor measures the pressure inside the airbox. From this pressure the air density is calculated, and when added to other inputs to the ECM, the engine load is calculated.  With this information the amount of fuel per injection is adjusted..."  

The ECM uses the temp of the air on the box vs the pressure at the intake to calculate the amount of oxygen available and that plus engine temp and rpm tells it how hard the engine is working thus knowing how much fuel to inject.


Throttles wide open = low pressure throttles shut = ambient, or thereabouts.

Think about it,  if only ambient pressure was needed they wouldn't have gone to the trouble of connecting it to the airbox with a pipe eh?

[AK Tiger]

It's also seeing clean air (ie. no dirt).  A dirty hose could clog and that would be a bad thing.

If the ECU (AKA: PCM, VCM, ECM) is seeing a large differential pressure between the ambient pressure and air box pressure, somethin' isn't right.