+- Rawze.com: Rawze's ISX Technical Discussion and more (http://rawze.com/forums)
+-- Forum: Big Truck Technical Discussion... (/forumdisplay.php?fid=1)
+--- Forum: ISX Related Help (/forumdisplay.php?fid=68)
+--- Thread: cm871 engine brake prob (/showthread.php?tid=3966)
cm871 engine brake prob - wellrun - 01-06-2019
cm871 isx engine brake at 66% even when switch is at #3 position...2009 prostar
RE: cm871 engine brake prob - alamow - 01-06-2019
Check Oil pressure. The engine in the truck I drive has the same issue when oil pressure drops below 32 psi.
Do you have full engine brake when the engine is cold?
RE: cm871 engine brake prob - Rawze - 01-06-2019
(01-06-2019 )alamow Wrote: Check Oil pressure. The engine in the truck I drive has the same issue when oil pressure drops below 32 psi.
Do you have full engine brake when the engine is cold?
If your oil pressure is dropping down below 32 psi while driving then you have some serious problems there.
RE: cm871 engine brake prob - wellrun - 01-06-2019
Yes i have insite and it show 66% when the switch is in #3... it should be @100%
RE: cm871 engine brake prob - Nilao - 01-06-2019
Most likely a bad switch then.
RE: cm871 engine brake prob - in2trux - 01-08-2019
Could also be the engine brake harness.
1 bad clip and it will throw codes.
We were losing stage 3
Stage 1 and 2 worked fine. Stage 3, coded.
New harness, no more problem.
RE: cm871 engine brake prob - wellrun - 01-08-2019
no codes
RE: cm871 engine brake prob - Rawze - 01-09-2019
(01-06-2019 )wellrun Wrote: cm871 isx engine brake at 66% even when switch is at #3 position...2009 prostar
Bad programming can cause incorrect engine brake operation too.