+- MHH AUTO (https://mhhauto.com)
+-- Forum: MHH AUTO FORUMS. (https://mhhauto.com/Forum-MHH-AUTO-FORUMS)
+--- Forum: Trucks, Buses, CE, AG Software & Discussions (https://mhhauto.com/Forum-Trucks-Buses-CE-AG-Software-%C2%A0Discussions)
+---- Forum: Isuzu Heavy Duty (https://mhhauto.com/Forum-Isuzu-Heavy-Duty)
+---- Thread: HELP WITH ISUZU NPR CODE P0299. (/Thread-HELP-WITH-ISUZU-NPR-CODE-P0299)
HELP WITH ISUZU NPR CODE P0299. - Graglor - 08-10-2017
Hey guys. Any help would be great. This truck got dumped on our lap. It's a 2006 GMC NPR with a Isuzu 5.2L. Fault code is P0299, low turbo boost pressure.
Previous work done:
Replaced turbo.
Replaced boost pressure sensor.
We've pressure tested the intake pipes, hoses, and clamps. Tested harnesses, and confirmed 30 psi of boost while driving.
Any input is welcome.
RE: HELP WITH ISUZU NPR CODE P0299. - skitzo - 08-10-2017
do you have the org file from ecu, i can try to set boost pressure in software
RE: HELP WITH ISUZU NPR CODE P0299. - blackdragon125 - 08-10-2017
Does it have low power as I had one that seemed ok but just was gutless and same code it ended up needing injectors and then it ran great.
RE: HELP WITH ISUZU NPR CODE P0299. - Graglor - 08-10-2017
(08-10-2017, 03:09 AM)blackdragon125 Wrote: Does it have low power as I had one that seemed ok but just was gutless and same code it ended up needing injectors and then it ran great.
It seems to not want to up shift very well, but seems to have power to me. We don't normally work on this little stuff. It's a favor for a customer that I'm starting to regret lol.
(08-10-2017, 03:04 AM)skitzo Wrote: do you have the org file from ecu, i can try to set boost pressure in software
PM sent.
RE: HELP WITH ISUZU NPR CODE P0299. - Graglor - 08-26-2017
Solved. Just to update in case anyone ever comes across this.
2006 GMC W-Series with isuzu 5.2L. Intermittent fault code P0299 (low turbo boost pressure). We were using IDSS software for troubleshooting.
We found small leaks in the charge air cooler hoses and clamps. Replaced all clamps with spring loaded clamps, re-tested, no leaks. Fault still existed.
Compared all engine data (fuel, air, timing, boost, egr position, etc) at idle and at 1600 RPM and compared the readings to what the data list in the manual stated they should read. Cylinder balancing rate on three holes were at max tolerances. -5 to +5 is the spec. Ours were (at times) +6 on holes indicating failing injectors. Replaced all injectors, programed trim codes. fault still existed.
Customer brought over another truck for a brake job. So on a hail marry try I traded MAF (Mass Air Flow) which is also the IAT (Air Intake Temperature Sensor). Truck drove like a dream, code went away, and even shifts better.
All engine data regarding the original MAF sensor was in spec and read great with temperature, and air flow. Our best guess is that while driving, the ECM communicates with all these readings so fast that the slightest variance will create this fault.
Hope this helps someone one day. We lost our shirt on this job through stupid stubbornness, eating labor on a learning curve, and pride.
RE: HELP WITH ISUZU NPR CODE P0299. - krep1231 - 08-27-2017
Good catch, that's how we learn best to stick it out to the very end. Congrats to you.
RE: HELP WITH ISUZU NPR CODE P0299. - Isuzu - 08-27-2017
Aaaand, we have a winner! Congratulations on your success buddy. Also thank you for explanation.
RE: HELP WITH ISUZU NPR CODE P0299. - Graglor - 12-06-2017
Here's a link for a service manual. I uploaded the whole thing I bought online. I just used the setup file and it worked. Free for all, but please let me know if it works or not.
RE: HELP WITH ISUZU NPR CODE P0299. - Chicagomike - 01-25-2021
Any way you can re upload the service manual.