QSX cm2250 derating/bad tune

[308smk]

(05-28-2024 )JimT Wrote:  you changed the sensor, but have you inspected the wiring to/from the sensor back to the ECM for damage, corrosion, loose wires, etc...?

You're probably right about a bad delete, but there could still be a separate wiring/electrical issue related to that sensor.

So on this tractor, it's a OEM fitted sensor that they stick into the airbox, behind the secondary air filters. The usual ISX BAP sensor on the wiring harness on the intake manifold doesn't exist on this motor.

We were getting 14.2-14.3psi readings from the ambient air pressure sensor. Elevation is approx 250m above sea level (near Winnipeg) and doesn't change much. So we re assuming the sensor is good although I haven't traced the wiring back. It was running rough and rolling coal before it ever threw that code as well.

I think ive managed to track down what I need to get that file pulled and sent off here soon.