Threaded Mode | Linear Mode

Redland1

Had my truck go into a derate about an hour ago.Boost is 20 psi max.I’m wondering if I demandate it will the derate go away? I know it’s not the proper solution but I just started a new gig after being down a couple of months unrelated to the truck and if I take it to the shop I this soon after starting I lose my spot. The intake manifold pressure sensor code has been there for a while and was still boosting 40 psi before the egr codes popped up.

tree98

What engine are we talking about here? How long has it been making 40 pounds of boost? That's quite a but too much and can cause serious engine damage. If it's in derate because of a bad EGR valve or Wiring to it, then yea demandate will straighten you out. I know a bad EGR valve will cause high boost on an 870, not sure if it would do the same on an 871 or 2250/2350. I'm assuming you don't have an 870 since they don't have an IMAP sensor.

Redland1

(11-30-2022 )tree98 Wrote: What engine are we talking about here? How long has it been making 40 pounds of boost? That's quite a but too much and can cause serious engine damage. If it's in derate because of a bad EGR valve or Wiring to it, then yea demandate will straighten you out. I know a bad EGR valve will cause high boost on an 870, not sure if it would do the same on an 871 or 2250/2350. I'm assuming you don't have an 870 since they don't have an IMAP sensor.

04’ 870.Sorry I should have wrote 38psi.

windowrattler

I went snooping around and from previous posts I think it is an 870.

windowrattler

The 870 doesn't have an imap but separate temp and pressure sensors.

Redland1

Some new codes that popped up

Rawze

The engine brake fault is not normal. egr valve acting up will not cause this. That issue needs to be fixed.. likely a loose connector under the valve cover, those clips become loose. That or the engine brake plug saturated with oil/sludge due to blo-by.

The intake pressure sensor likely needs replacing. Might as well replace the other one and the exhaust pressure sensor, and check its feed circuit too.

Turbo inlet temp alarm above normal is usually an indication that the turbo is overheating or being abused in some way. Likely overheating due to low boost. -= Might also want though to ensure the exhaust muffler is not getting plugged up. If it is more than 8-10 years old and has a million+ on it, .. its time to replace the muffler while your at fixing the rest.

As far as the egr valve... forum member 'running rough' does CM870's for people on here.

Might also want to do a turbo inspection etc. while your at it too.