Doug Stoker Posted October 21, 2021 Share Posted October 21, 2021 2007 mack granite cv713 tri axle dump with an Allison. Truck started to idle low couple months back. Idles at 500 rpm. Since then changed 6 injectors. throws a 8-3 blink code occasionally. changed that EUP, however still idles at 500 rpm. ABS light has been on for a while truck runs fine. Just cannot figure out that low idle. Any help would be appreciated Quote Link to comment Share on other sites More sharing options...
880joe Posted October 21, 2021 Share Posted October 21, 2021 I had a 92 CH Mack that did that if I remember correctly they told me that somebody was probably poking the cruise control switch mutipal times quickly and caused a default code so I took it to mack and had it reset never caused problems after that Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted October 21, 2021 Share Posted October 21, 2021 I cant think of why the idle speed would change on its own, any recent programming been done? Idle speed is easy to reset with Mack software. 880 Joe may be on to something here... I'd like to know, jojo Quote Link to comment Share on other sites More sharing options...
Onyx610 Posted October 21, 2021 Share Posted October 21, 2021 Any possibility it’s idling where it needs to be and the tach is just off? Or does it noticeably sound different? 1 Quote Link to comment Share on other sites More sharing options...
fjh Posted October 22, 2021 Share Posted October 22, 2021 (edited) 16 hours ago, 880joe said: I had a 92 CH Mack that did that if I remember correctly they told me that somebody was probably poking the cruise control switch mutipal times quickly and caused a default code so I took it to mack and had it reset never caused problems after that Yup seen this happen many times with Allison equiped units just a hicup in the program settings! take it to a mack dealer have the dealer program the idle back to 650 and turn off the parameter to set the idle with switches! this parameter requires you to hit the clutch switch to set the idle ! you have no clutch pedal so your unable to finish the set sequence! Edited October 22, 2021 by fjh 1 Quote Link to comment Share on other sites More sharing options...
Mackpro Posted October 22, 2021 Share Posted October 22, 2021 https://f01.justanswer.com/diesel3153/b783e0a3-7099-4672-8fa2-def5c4dff508_Mack_engine_speed_control.pdf Follow instructions on bottom of page 1 and top of page 2 . Common issue Quote Link to comment Share on other sites More sharing options...
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