I been looking talking and just staring at my truck hopefully y'all can help here's what I have this is 3 post I made on another site but didn't have any help
p0234 turbo over boost
I recently bought a 2001 4x4 3500 Silverado with the lb7 240,000 miles truck is stock other than magnaflow muffler and nicktane cat fuel filter. I am having trouble with the truck going into limp mode. if there is no load on the truck it runs great I drove it 1,000 mile trip not one hiccup. if there is a load on truck I typically haul 11,000 lbs +- not every time but most times in a steady pull hwy speed 55-75 mph truck will go into limp mode ses light does not always illuminate but code p0234 will be in system I have read countless post with no luck here's things I have done
flashed all modules to current chevy calibrations
replaced one turbo boot? at intercooler had tiny tiny hole from batt acid
cleaned maf sensor very dirty from previous owner he had k&n filter I put stock filter element in problem still occurred maf read correct at idle but since there was no test at wot etc. I replaced maf no help
followed flow chart on code
vacuum line to gate actuator good
actuator holds vacuum
with 20-30 psi gate moves little but not a lot I can bump with spray nozzle and it swings further
did not take actuator off but can move gate with pliers
checked baro vs boost was ok
checked harness from boost sensor to ecm found no problems
no air leaks via smoke test
replaced boost sensor (put a ordinary chevy map sensor by mistake chose wrong one on napa site physical match but truck did not like it thought I was going to have to push it ha)
tubo sound good truck has tons of power don't think its a mechanical problem
I took pictures of my freeze frame data I will try to upload I would appreciate any help im good at hitting things with a hammer but takes me a while staring at a scanner to make heads or tails
one thing I checked was all other modules I found a history code in the body control module, the inst. cluster, and the air bag module of u1016 so unless im reading alldata wrong this is a communication problem with the pcm not these modules so im going to try to check all grounds tonight I cleaned and replaced battery bolts when I bought it
well I fixed some bad grounds today added several where I thought there should be some and of course that didn't fix anything I would like someone to check behind me but isn't the boost reading normal according to my freeze frame I thought you subtract the baro from boost then convert to psi and you have boost pressure? so my truck is boosting 14-15 psi when shutting down correct? boost limit is 25 ish psi? would this point to bad ecm? any help is very appreciated thanks, Sam
p0234 turbo over boost
I recently bought a 2001 4x4 3500 Silverado with the lb7 240,000 miles truck is stock other than magnaflow muffler and nicktane cat fuel filter. I am having trouble with the truck going into limp mode. if there is no load on the truck it runs great I drove it 1,000 mile trip not one hiccup. if there is a load on truck I typically haul 11,000 lbs +- not every time but most times in a steady pull hwy speed 55-75 mph truck will go into limp mode ses light does not always illuminate but code p0234 will be in system I have read countless post with no luck here's things I have done
flashed all modules to current chevy calibrations
replaced one turbo boot? at intercooler had tiny tiny hole from batt acid
cleaned maf sensor very dirty from previous owner he had k&n filter I put stock filter element in problem still occurred maf read correct at idle but since there was no test at wot etc. I replaced maf no help
followed flow chart on code
vacuum line to gate actuator good
actuator holds vacuum
with 20-30 psi gate moves little but not a lot I can bump with spray nozzle and it swings further
did not take actuator off but can move gate with pliers
checked baro vs boost was ok
checked harness from boost sensor to ecm found no problems
no air leaks via smoke test
replaced boost sensor (put a ordinary chevy map sensor by mistake chose wrong one on napa site physical match but truck did not like it thought I was going to have to push it ha)
tubo sound good truck has tons of power don't think its a mechanical problem
I took pictures of my freeze frame data I will try to upload I would appreciate any help im good at hitting things with a hammer but takes me a while staring at a scanner to make heads or tails
one thing I checked was all other modules I found a history code in the body control module, the inst. cluster, and the air bag module of u1016 so unless im reading alldata wrong this is a communication problem with the pcm not these modules so im going to try to check all grounds tonight I cleaned and replaced battery bolts when I bought it
well I fixed some bad grounds today added several where I thought there should be some and of course that didn't fix anything I would like someone to check behind me but isn't the boost reading normal according to my freeze frame I thought you subtract the baro from boost then convert to psi and you have boost pressure? so my truck is boosting 14-15 psi when shutting down correct? boost limit is 25 ish psi? would this point to bad ecm? any help is very appreciated thanks, Sam
