The dreaded 2009 Enclave 3.6l

I recently rebuilt the front end of my in-laws 2009 Enclave, after replacing the structural damage and making it look good my daughter drove it for a few weeks. One night she calls in a panic stating the car wouldn’t run properly. After towing it home I looked up the service bulletins in the vehicle and about passed out. I believe there were over 1500.


So far I’ve pulled off the top of of the engine to check the timing chains, they’re good and we’re replaced by the previous owner. Asit has 168,000 miles, I cleaned and bench tested the injectors and coils, sensors,VVT solenoids, ran through the fuel system, smoked the EVAP system and generally checked everything I was capable of checking. In the process I replace the following as their continued viability was in question: Evap Canister and solenoid, low pressure fuel pump, high pressure fuel pump, crank sensors, anti-knock sensors, spark plugs, battery, several hoses, all fuel injector seals, gas cap, air flow sensor, high pressure fuel sensor, checked dozens of electrical connectors, redid all the grounds I could access, changed all fluids (yes all) and did other general maintenance items.

when it first went into limp model it was throwing multiple codes, no I don’t have the list, it was in my scan tool that some took from my garage while I was under a vehicle, so now I’m relying on my old XTools A30M. The vehicle ran great for about a week, now it won’t start. I went through the process outlined in a service bulletin for checking a system that won’t hold 60 psi of pressure. I was getting a low voltage code on the high pressure fuel sensor too…but it magically went away.

I now have no codes, a message for low right rear tire pressure, and an illuminated check engine light. I just replaced the fuel…it still won’t start. Any suggestions would be appreciated.