Currently working on getting my truck running. Its a LQ9 converted to Gen 4 with reluctor wheel and Cam gear. Also matching Gen 4 sensors. E38 ECU and wiring harness from a 2009 6.2 caddy and 2007 GMC 6L80. Finally got the MPV tonight and times to hunt down all my issues. Starting off strong with a Detcect Protocol Failed. This is all new to me and im trying to learn as I go here. What are my next steps? I followed the HP tuners website advice to no answer
What is 'my truck'? I know you know what it is, but nobody else does unless you tell us.
Do you get a check engine light at key-on? Fuel pump prime? Power to pin 16 in the DLC?
Well my truck is a 94 ford ranger that was ECC1 so it's really not too relevant I think.
Knowing it’s a swap vehicle is very relevant.
LOL Yeah, detect protocol failed in a swap vehicle. The fact that it's a swap vehicle is irrelevant LOLOL.
EFI specialist
Advanced diagnostics, tuning, emissions
HPtuners dealer and tech support
email=[email protected]
Do you get a check engine light at key-on? Fuel pump prime? Power to pin 16 in the DLC?
I'll just keep re-posting this until you decide to answer.
No power on pin 16 of the ob2 port? Because that would be a no vehicle power detected? This build is brand new, the ECU still believes its a 09 Escalade and i doubt it will fire the fuel pump without all the safety interlocks turned off. Everything comes to life with key on and will crank the motor. I do currently have a voltage back feed issue somewhere so possibly noise into the canbus network. Although my digital dash still reads the sensor inputs. I am gong to try a scan tool and see if that recognizes the ecu.Originally Posted by blindsquirrel
DLC #16 should be powered by the fuse block.
You need to know if the ECM is waking up to decide which direction to go. Fuel pump should prime regardless of VATS condition when the ECM powers up; VATS only shuts off injector pulse, not the fuel pump or spark or anything else. Whether the starter engages or not depends on whether you are using the key to request cranking from the ECM or if the key goes direct to the solenoid (if the ECM is not controlling the starter then it would have no way to interrupt that).
Grounds are just as important as yer hots.
EFI specialist
Advanced diagnostics, tuning, emissions
HPtuners dealer and tech support
email=[email protected]
Thank you that helps. I'm going to pull up the caddy wiring diagram and do some more digging and see if i missed anything
Check for ECM pin X1.18 - High Speed Communication Enable which is actually Accessory voltage.
Without powering this pin ECM will not communicate.
2011 Cadillac Escalade L94 w/LS3 valves and valve springs
Update to everything. Spent a lot of time learning here. I messed up my wiring combined with a pretty damaged harness. I gutted everything and start over fresh. Redid my body wiring harness and verified everything worked. I bought and re pinned my own harness for the motor side and spent a good amount of time learning what everything does. My Mistake was thinking the canbus network is a bundle of snakes. Instead its a pretty clear daisy chain system.
It now goes OBD2 port w/ resistor - 6L80e - e38 ECU. Not retaining body control module so I also swapped to a 4 wire alternator instead of two wire.
Here's my 6L80e wiring if anyone wants to double check it. Transmission plug first then circuit and where it goes.
Based on a 2008 4x4 6L80e truck
#1 na
#2 na
#3 park/neutral signal- circuit #- X1 Pin 1
#4 12v+ 24/7 - 1840 - battery 10 amp fuse
#5 ground - 1551 - front right cylinder head
#6 brake switch - 6311 - brake relay
#7 na
#8 na
#9 accessory wake up - 5985 - x1 pin 18/ normally 12+ w/ key on from BCM
(This one i need to double check on the truck) i have no BCM anymore
#10 canbus + - 2500 - x1 pin 27
#11 canbus - -2501 - x1 pin 28
#12 ignition voltage - - pink wire 15 amp switched w/ key
#13 canbus - -2501- obd2 port #6
#14 canbus + -2500 - obd2 port #14
#15 na
#16 Rep TOS signal -6399- x1 pin 71
Reply With Quote