Hello everyone my name is Preston and I am new to HPTuners and new to the forum so I will start off with the detail and what I have tried so far. Vehicle is a 2005 Chevrolet Suburban 5.3l 4wd Vin Z L59 engine and P59 pcm. I recently pulled the engine and replaced all the leaking gaskets top to bottom with exception of the head gasket as I didn't want to go that far into the engine. When I did all the gaskets I replaced the knock sensors and harness because the existing ones looked tired, but they never gave me issues. Also did new spark plugs and wires. Mods I've done during this were SacCityCorvette billet oil diverter, Summit SUM-8701 cam, Pac-1218 springs.
Cam specs: Stage 2 LS Truck Swap Cam, 218/227 112+2, .523/.524 Lift
Now on to the issue I've been having. On initial start-up I obviously had issues with idle, also set a P0327 and P0332 I think they were. Got the initial idle set so I could move on. Tuned the MAF first then moved to the VE table. After this the P0327 and P0332 went away, but I acquired a P0300 random misfire code at idle that I came to the conclusion was because of the cam so I adjust the misfire detection and got it under control. At this point I notice some weird things with acceleration and did some adjustment on Torque Management and smoothed the acceleration.
Finally I got to tuning the timing table. I started to add in timing and saw no Knock Retard at points where I'm sure there should have been some. At one point I chose a point in the rpm range and advanced it by 14 degrees and could audibly hear knock, but still showed nothing on the table. When I say audibly I mean I could hear it through a DIY set of det phones I made for another project that does not have a knock sensor factory. At this point I contacted HPTuners to see if it was in the software and tech support said everything looked good with my scanner setup, so I set out to checking the knock sensors. Both sensors ohm out fine and with a DVOM I do get a change in AC voltage. I know I should be checking them with a scope, but that is all I have personally. I will note the knock sensors are not OE and I have seen people say they had issues with aftermarket sensors. I don't believe that is my issue though. While checking the sensors I also wanted to check the harness to the PCM, but I can't find a reliable wiring diagram. In attempts to eliminate variables I decided to load my very first tune just after get the idle set so I could drive it without it trying to die when coming to a stop or during low speed turns and unplugged the knock sensor harness where it plugs into the main harness at the top of the intake manifold. I have completed no less than 10 drive cycles and show no DTCs for knock sensors in stored or pending which I find odd.
So at this point I did some searching and found a module called a Knock Control Module part number ACDelco 216-64 and several places show it to fit my vehicle. I cannot find a location or a wiring diagram that depicts it or even mentions it. In the part description for that parts it sounds like the knock sensors report to it and it send a signal to the PCM to set a code. So my conclusion is that part has fail so the PCM never gets a signal to give a code for the knock sensors. Any insight from you guys into this problem wold be greatly appreciated.
Thanks in advance,
Preston.