Jake brake long delay

[JimT]

(05-25-2021 )Redland1 Wrote:  Messed around with all the wires under the hood especially the ones coming out of the ECM and now the Jake brake works.

You said it's a 2004 cm870. Maybe try tapping on the ECM while the truck is running. I think the recommendation is lightly with a hammer? (Someone correct me if I'm wrong) Maybe seeing symptoms of an ECM going out? Could also be bad contact, corrosion or bad wires with the wiring harness or it's connector/plug.

Also, not sure if it was mentioned already, but you said it started after you changed a few sensors. Might want to go back and make sure each of the sensors were plugged in fully and correctly, check the plugs for corrosion or anything else that might short the wires or interfere with the electrical circuit. Finally, you can follow the steps in quickserve/insite for troubleshooting the sensors using a multimeter. I would check all the new sensors in addition to the ones throwing the errors.