M5660SU won't throttle down

Jack Frost

New member

Equipment
B2601,M5660,ZTD
Apr 30, 2025
1
0
1
Hardeeville SC
My unit is about 6 years old; well maintained; for the last few months, it will not throttle down. When it starts, no matter where the throttle lever is, it starts at full power. The pedal on the floor moves freely. Moving the throttle has no effect on the RPM's. Before I go to the trouble of loading it on a trailer, any thoughts where to start? TIA
 

Fedup

Active member
Apr 6, 2016
371
147
43
Winchester
No authority on common rails systems but I would start with a service manual and investigate the throttle position sensor values and the related circuit. The computer could be getting a signal that the throttle is indeed wide open and reacts accordingly. I would locate the sensor, unplug it and see if it will even start with that out of the loop.
 

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
36,365
11,175
113
Sandpoint, ID
Check all of the linkage:

1788664946065.png

Look in the WSM how to test this switch:

1788665070080.png