Hello all have a 03 flex fuel suburban. Been trying to get my cel off so can get inspection done. The codes I have coming up are p0178 flex fuel sensor circuit low input. And u1000 class 2 data link malfunction. I checked the wiring to the flex fuel sensor plug. Ground wire the black of course no power the white signal wire 5.x volts. Red power wire 0 volts. So something is up for sure. Checked all fuses under hood and side of dash. Not knowing this I purchased a Dsp simulator but since no power to it it wouldn't work regardless. My cel was coming back on after 3 miles. So I decided to try something. I ran a ignition on wire to the red power to the connector and for 10 miles no cel. Then this morning I fire it up and after 2 miles the cel is on. Haven't checked it yet as I am at work. But I assume it will be the same codes. Any idea guys ?


Update buddy at work had his scanner p0141 heater circuit bank 1 sensor 2. So maybe the 02 sensor is fried. And my back job repair may be holding.

 

Replaced sensor with a new one last night. Today engine light is back on after clearing it. P0141 heater circuit. Bank 1 sensor 2 is code. So I replaced driver post cat sensor. I don't get it

 

the 02 heaters power are from a fused power source in the uh fuse box. check the fuse.

 

Will do thank you

 

Alright guys. I went under the vehicle again and started looking at wires. I found three wires broken. One red power to flex fuel sensor connector. Two to the rear o2 sensor bank 1. Repaired them now I have power source to them. Now time to drive it and hope all is well.