Jason Norris

I have a strange one. I bought a truck that had engine issues. Upon diagnosis, cylinders 4 and 6 were misfiring consistently. I verified fuel and spark, performed an injector balance test and it was fine. Verified spark as well. Viewed wave forms with my Picoscope and they were normal. Checked compression on both cylinders and it was 175 psi. Pulled the valve over and all rockers are operating normally. Engine had a P0300 code and a flashing MIL indicator. O2 readings were very erratic with both sensor 1's on both banks were reading very low or down to zero and the bank 1 sensor two stayed at zero and bank 2 sensor 2 was around 100 volts. I found a chafed wire on B1 S2 but didn't see any copper. I unplugged sensor 1 bank 1 ans was going to check power and ground but decided to pull the sensor but it's stuck so I plugged it back in. Went back up to the top of the engine and noticed the ground strap from the left rear of the cylinder head to the firewall was green and I pulled on it and I noticed the strap was loose at the back of the head so I cleaned and tightened it. I started the truck again and misfires are all gone and the O2's are working normally which is s good thing however I don't know why. With the engine running I disconnected the ground strap and it still ran fine. I did notice it sparked when I put it back on and not sure of that is normal. \ I'm posting this to see if anyone chased a misfire and had a ground that was the issue. I don't know if the O2's were reading lean because the engine was running with misfires or if the misfires were the result of poor O2 performance. The sensors are grounded through the ECM. I also have a P0521 oil pressure performance code and noticed the oil pressure viewed in the scanner is 11 psi at idle.

Thanks. My button block comes tomorrow.

Wow fantastic thank you! Buttons will be here tomorrow

You were right! The connector is there. I’m going to get a button set and see if it works. Hopefully the cluster is programmed for it. I saw a video where the guy just ran wires from the connector and tapped it to ground to toggle through the fuel mileage and vehicle settings and one of the options was doors lock in gear. But it was on a 2004. Not sure if the 2009 works the same way or if it uses resistors. I’m not savvy with wiring diagram symbols

Very interesting. I’m going to look now.

Hmmm. So your saying the connector is there for the dic even if the truck didn’t come with it?

Yes I have. It says to use the did buttons. If I added them, where would they plug into?

If it does, I can’t figure it out. The only option I can access is the language.

I did look and it only talks about accessing it through the DIC which I don’t have. I saw a video on how to do it on earlier models by holding the high beam indicator back and cycling the key twice but it doesn’t work.

My doors won’t automatically lock when shifted out of park. They will unlock when shifted into park though. I have a base model and there is no programming feature available. I looked at wiring diagrams but can’t see where the bcm gets its signal to lock from the gear selector or p/n switch. Does anyone have any ideas on how to diagnose?

I found one and they don’t seem to share a common ground but I could not be understanding the diagram

Thanks. I’ll search for one online. I don’t have a service manual for it.

2009 Sierra 2500hd has an issue where it throws multiple codes intermittently. It then goes into limp mode. The codes are: P0016 CRANKSHAFT POSITION AND CAM POSITION CORRELATION P0068 THROTTLE BODY AIRFLOW PERFORMANCE P0101 MASS AIRFLOW SENSOR PERFORMANCE P0106 MAP SENSOR PERFORMANCE P0513 THEFT DETERRENT KEY INCORRECT I wouldn’t expect all these codes at once. With the key code, is it possible that it’s misreading the key and the limp mode is a result of that? Would the limp mode cause the other codes? This seems way more involved than just a simple sensor. I’m familiar with all the sensors and what they do but no idea why they all come at once. Possible bad ecu?

I don't want the headlights on when they are not supposed to be. Only the dash lights to work based on variable voltage as supplied by the dimmer switch. Basically, how do I make the headlight switch supply voltage to the dash at all times?

I have Dmax swapped Hummer H2 with the appropriate diesel cluster. I had a customized with LED lights and a black face with white numbering/lettering. I have a hard time reading the gauges in the day and would like to keep them illuminated all the time. Does anyone know if I can jump a wire to make this happen other than keeping the lights on all the time?