2011 Chevrolet Avalanche V8 engine no start stalls and mil lamp on
2011 Chevrolet Avalanche V8 has check engine light on, stalls occasionally and it won't start. If I let it sit for 3-4 hours, it
will start. When it acting up, all lights in the dash panel are on and when I tried scanning for codes, I have a U fault codes
which are mostly no communication codes:
U0101-Lost Communication with TCM
U0102-Lost Communication with Transfer Case Control Module
00109-Lost Communication With Fuel Pump Control Module "A"
There are a few possibilities for this problem:
1.) Faulty in high speed modules especially the BCM or its components. Try unplugging the BCM and see ohm reading at pin 6 and 14 terminals at DLC.
2.) Failure in ECM which might require replacement of the crank sensor. What is your vref at crank? Do the vref voltage reading at a sensor that can be easily accessed like tps, crank or cam sensor.
3.) Failure in class 2 serial communication bus line. Hook up a voltmeter on pin 1 of the DLC against pin 5 and compare measure voltage at KOEO for all modules at splice 1 or JX221. Any module with a different voltage reading is the culprit.
Take note that the 2011 model has 2 additional bus wires added to the previous 6 bus wires in the 2008 model: LIN bus wire and low speed serial data bus wires. You will see this clearly in the wiring diagram if you get the specific application of your truck.
More GM Communication problem tips!