Thread: Topped swapped 06 GP now wont start and scan tool wont comm with ECM

Hello i just completed a top swap on my 06 GP and ran into a few hick ups that i was so fare able to correct. I did a complete rebuild along with top swap and put assembly back in and now car will not start. I bench tested the Crank and Ignition relay and they click and i tested the pcm and ignition fuse to ground and get source voltage. I ended up getting a jumper wire and tested for power at starter solenoid during cranking and only get a couple millivolts. i left the jumper there and put the other end to power at the battery and the car starts fine but idle is rough. There is a CEL illuminated but my scanner cannot pull it up while car is running or KOEO. it just says link error. ( using a Actron)

When running the dash, radio and DIC goes off and the CEl light is the only thing that is illuminated. When i cut off the ignition the dash comes back on, radio lights up and DIC also returns. My DIC keeps reading Service engine soon, low fuel level and charging system failure. I took the battery to oreillys to get load tested and passed ( battery is a optima yellow top) and i have the battery hooked up to a trickle charger at 2 amp and before i jump the solenoid i change it to jump start 50 amp on the charger. i took the starter in to Oreilly's as well and passed. Also i have added about 10 gallons of fuel and also had a about a 1/4 tank before i pulled the motor.

I ohmed out the purple serial data wire from the DLC to the Splice pack and get between .4 to .6 ohms. I get source voltages at the onstar LDL fuse and scan tool lights up fine just will not communicate. The Grounds are secure and illuminates my 12V test light when i connect the end to battery power. When I turn the key to crank can here a relay click as well.

ECM was tuned by zzp before installation and i had the battery disconnected before reinstallation. i have two other ecm's with N/A tunes and they do the same thing when connected.

Im stumped and have been troubleshooting for weeks. It worked fine before i pulled the motor; any ideas.

Thanks in advance

Does the car crank at all?

No the car does not crank at all. I can hear a click from the fuse box when i turn the key. I have inspected the trans and battery chassis ground and cleaned them and applied dielectric grease. I also used a 12volt test light to see if they are sufficient grounds. I tested the BCM and DLC grounds too. after i jump the solenoid to get it started the radio, dash and DIC turn off but the CEL illuminates. Cannot get actron to hook up though reads link error.

Also once its running i get no throttle response. I try to snap the throttle nothing happens.

Originally Posted by Scottydoggs

check the fuse box for a blown fuse, the cig lighter fuse also works the obd2 port.

did you take the starter off? maybe the wires are on wrong? you got 3 grounds on the trans bell housing? maybe one broke off? or the loop is loose, we've seen that one before.

as far as the throttle response, you got all the vac lines hooked up correctly?

I will recheck all fuses. but on the wiring diagram for my 06 the power to the DLC comes from the Onstar ALDL fuse and has power at fuse and orange wire. i have tested the pin at the DLC to ground and get source voltage. The scan tool turns on but just does not communicate.

Yes the starter was off and i verified the wiring. my model does not have ABS so one of the grounds that goes to the transmission is not on my model like the ones with ABS. Good question on the vacuum line routing i will verify that next.

A little side not though on my top swap i did not swap over GTP wiring. so i dont have the wiring for the TC on the BBV and using the stock Map wiring to the 2 bar map from a GTP and do not have the BAP sensor wiring/ sensor either. COuld that cause an issue i informed zzp this when i sent the ecm in for tuning.

I found a vacuum leak at the BBV where the harness is to go for the Traction control. I thought they were plugged and were not on both ends. I looped a vacuum hose around so they pull straight vacuum. I may need to resize the vacuum hose on the Map. I noticed that the stock map vacuum hose is about 5 times thinner that what im using. Right now it is not starting when i jump the starter. im gonna dis connect every sensor and reconnect it. I will also follow DBextreme advise and check the wiring on the Map harness.

Also mine does not go into relearn the security light never flashes. I attempted the relearn several times with no luck. I am also trying to get responses from members who have 06's and see what they did different to get theres to run.

Thank you all for your help.

I fixed it it was the wiring harness. I reached out ot Turbo Tim at ZZP and he advised that he had tuned the ECM with an 05 GTP bin file. I went to Morad and purchased a 05 GTP Engine harness and installed it on Wednesday night and it started on its own and idled fine. a little loppy due to the VS cam. Last night i was running it and got code P0336 for Crank sensor. I think i may have chaffed the wiring at the CKP it is hard to keep it tucked with the Super belt in pulleys in the way.

Originally Posted by dbextreme

I'd check your wiring. When I did my top swap I purchased the swap kit that came with the MAP stuff and the BBV sol pig tail. The MAP harness was wired backwards (outer pins were swapped so instead of wiring A -> A, B -> B, and C -> C it was A -> C, B -> B, and C -> A) It caused mass confusion and I didn't notices it until I broke out the volt meter and started testing ends... Heck it was throwing a code for the gas tank... LOL But something simple like that can throw everything out of wack.

Also I have my BBV hooked to run complete off vacuum. Here is a diagram of what mine looks like. I assume you swapped a Gen V top on your L26 and not the Gen III so yours will be a bit different but around the BBV should be the same..

http://i698.photobucket.com/albums/v...220_172842.jpg

What I'm wondering is it being an 06, is it a security thing? My Intense PCM came with the VATS/Security and Crank Pos Sensor relearn procedure.