Jake Brake Problems
I have a 2004 CC Intrigue w/ 400 ISL. High or low on the switch the Jake comes on in low mode and trans downshifts to 4th gear. That's all I get.
First I had the trans reprogramed at Allison repair to shift down to 2nd gear. Works much better
Second I traced the electric from the switch to the relay then to the engine. Here I found the 2 prong plug that connects the switch to the ECM had one corroded terminal. I cut the plug out and direct connected the wires and I now have low and high jake