Error Code P0264

[CraigOD]

I have a 2018 Silverado LT/Z71 with about 8500 miles. I purchased the truck new in March.  About a week after I got the vehicle it had roughly 500 miles and it threw an error code P0264 among many others. I had the truck checked out by a GM dealership, and they changed all the injectors  and did some other work. The fix lasted about two months, 1500 miles and the truck did the same thing. This time the same dealership said it wasn't the injectors but a faulty wire. They replaced the faulty wire and everything checked out. This time the fix lasted until two days ago. the truck now has about 8500 miles, and it threw the same error code. Lucky I was at home, so it hasn't had a chance the throw the other error codes, but I'm sure if I drive it, it will throw all the usual codes. so far everything has been covered under warranty but it's getting a little old, and I'm more concerned with what happens when the truck runs out of warranty. I have contacted the dealership I bought the truck from about a new truck, so were currently working on that. Has anyone experienced the same issue, or have any advice. Thanks for the help.  

[jay webb]

looks like a wiring/harness or ecm issue. 

1. Ignition OFF, all vehicle systems OFF, disconnect the X3 harness connector at the K20 Engine Control Module. It may take up to 2 min for all vehicle systems to power down.
2. Test for infinite resistance between the appropriate Q17 Fuel Injector high control circuit and ground.
   • If less than infinite resistance
   1. Disconnect the harness connector of the Q17 Fuel Injector.
   2. Test for infinite resistance between the Q17 Fuel Injector high control circuit and ground.
      • If less than infinite, repair the short to ground in the circuit.
      • If infinite resistance
   3. Test for infinite resistance between the Q17 Fuel Injector low control circuit and ground.
      • If less than infinite, repair the short to ground in the circuit.
      • If infinite, test or replace the Q17 Fuel Injector.
   • If infinite resistance
3. Ignition ON.
4. Test for less than 1 V between the Q17 Fuel Injector high control circuit and ground.
   • If 1 V or greater
   1. Disconnect the harness connector of the Q17 Fuel Injector, ignition ON.
   2. Test for less than 1 V between the Q17 Fuel Injector high control circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, repair the short to voltage on the low control circuit.
   • If less than 1 V
5. Ignition OFF.
6. Test for less than 10 Ω between the Q17 fuel injector high control circuit and low control circuit.
   • If 10 Ω or greater
   1. Disconnect the harness connector of the Q17 Fuel Injector.
   2. Test for less than 2 Ω on the high control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω
   3. Test for less than 2 Ω on the low control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, test or replace the Q17 Fuel Injector.
   • If less than 10 Ω
7. Test or replace the K20 Engine Control Module.