SSG Private RallyPoint Member 703347 <div class="images-v2-count-0"></div>I'd like to know if anyone has had any issues with a M978A4 HEMTT going into high idle or why you go to engage the high idle in the back when you are pumping fuel and it won't idle up. Then when you look that the panel in the cab and the high idle is lite but it's not turned on. 2015-05-28T16:14:23-04:00 SSG Private RallyPoint Member 703347

<div class="images-v2-count-0"></div>I'd like to know if anyone has had any issues with a M978A4 HEMTT going into high idle or why you go to engage the high idle in the back when you are pumping fuel and it won't idle up. Then when you look that the panel in the cab and the high idle is lite but it's not turned on.

2015-05-28T16:14:23-04:00 2015-05-28T16:14:23-04:00 SGT Heath Johns 2083742

<div class="images-v2-count-0"></div>Had issues with this in Germany, once the A4&#39;s took over our mechanics were on over drive trying to break this issue down. Ended up being the switch. Not sure if it was contacts, or wiring, but that&#39;ll be your source. If nothing there, check the throttle plate and wiring to see if something is wrong there.

2016-11-17T11:57:20-05:00 2016-11-17T11:57:20-05:00 SGT Private RallyPoint Member 2594491

<div class="images-v2-count-0"></div>Double check to make sure transmission is in neutral. If it is in gear, high idle will not engage from the rear of the truck even if switch in cab is on.

2017-05-23T22:15:12-04:00 2017-05-23T22:15:12-04:00 2015-05-28T16:14:23-04:00