ISM500 Barometric Ambient Air Sensor

[mayhem1]

I have a 2003 Pierce fire/ladder truck that shows barometric ambient air temp sensor bad. Everything I have read says its located around ecm/fuel pump area. I cannot find this sensor at all. Simple fix if i can find. One rep said it's older style sensor that is held on with 2 6mm bolts above fuel pump. Cummins sent a 2897331. Any suggestions?

[Rawze]

- Depends on where the truck-maker installed it. Some are buried inside the engine wiring harness, some out in the front under the bumper, some are in the drivers side or passenger side mirror on some model trucks.

I am thinking it is in the engine wiring harness. maybe buy a replacement and see if you can find the same sensor along the harness somewhere zip-tied up and painted over.

maybe look on quickserv and see if you can see it on the drawing for the ecm wiring harness... or if it shows it in the engine overview diagrams. .. quickserv is free to join.