Got the new radiator put in, engine flushed, and new coolant installed. Ask the garage to check why I was getting the CEL and p0101 code. They said they couldn't figure anything out. So I got in my truck and left. Drove the half hour home with no issues. Truck is still running about 215-217 consistently.

Got in the truck the next day and drove about 15 miles and check engine light came on. This time it was followed by REDUCED POWER showing on the DIC. So I pulled over and the engine was chugging and sounded horrible. I shut it down and fired up Torque in my phone. This time, in addition to the p0101 code, I also had a P0068.

The p0101 code is a mass air flow problem, so I replaced the MAF sensor several weeks ago and it didn't stop the code. The p0068 says Throttle Position Sensor Inconsistent with the Mass Air Flow Sensor. But the H3 does not have a serviceable Throttle Position Sensor. I have searched the forum and found no mention of a p0068. Does anyone have any experience with these issues I am having?

This truck has been almost flawless for years and now it is just plagued with issues. I'm sure it is a simple fix if I can just figure out what it is.

 

check for a vacuum leak. GL

 

No vacuum leaks. Not that I could find anyway. I used starting fluid and got no surges anywhere. Where are the most likely leaks to be found.

If there are no leaks, what would be the next likely candidate? This thing is running rough. And I'm down to just over 14mpg on the interstate, driving easy.

 

Since you already replaced the MAF, 1 thing both codes have in common: vacuum leak.. Did you check around the intake manifold gasket? If leak is found there, could be loose bolts, just tighten.

You should have just cleaned the MAF sensor first, check and make sure the connector wires are not damaged and make sure the contacts are clean and secure.

The p0068 points towards a dirty throttle body, vacuum leak, or defective MAP (manifold absolute pressure) sensor...


You can check for more information and possible causes by entering your code here:

(just remember codes are "P" and "numbers", type your code in the search box and click on the code listed for results, they even list vehicle manufacturer specific)

OBD2-OBDII Engine Light Trouble Codes Definitions, Description and Repair Information | Engine-Codes.com GL

 

Thanks buddy. Back out into the cold!

 

cold in tenne? I was out in the garage today working on my neighbors snowblower, temp was is in the teens. Goin' below zero in the next couple days... I'll take your 40's anytime...


Also make sure you check those wires around the map sensor... Check to see if there has been any rodent activity around your engine... I've seen it many times, rodents get up on customer's engines and chew on wiring....

Another thing to consider, is your air intake secure from the MAF to the throttle body?

GL

 

Yeah, it's pretty decent during the day. Single digits at night. I'm actually down in my hometown in GA right now. Was hoping to take the Hummer to the mountains to play in the snow. Don't want to try till I get this figured out though. I'll try those latest things tomorrow.

 

make sure to take the throttle body off so that you can clean both sides of it properly.

 

Yeah, I did that. It did help. I don't know how it happened, but apparently I sucked up some of the DexCool gunk into the air box and throttle body when my radiator was leaking. But still getting the p0101 code within a mile when I start driving. I ordered all new Delco coils yesterday and I will clean and/or replace plugs when I am changing them. If that doesn't work. Next step, I'll try to replace the MAP sensor. After that I don't know...

Then I'll get back on the Stab Sys errors! haha

 

When it rains, it pours. Got stranded on the side of the road a couple of nights ago. Nothing to do with the other problems I have been having. Going along and the trams starts to slip. Pulled over and had a huge puddle of trans fluid on the ground. In the dark, I at first thought it was coolant because it was at the front of the truck. Turns out it was just a line on the trans cooler. Apparently, the mechanics didn't tighten it back down when they installed the new radiator. Got it out back on and replaced 5 quarts of lost fluid. Seems to be no permanent damage to the trans so far. I am burned out on these constant issues. I guess maybe it is better to have everything happen at once on an otherwise great vehicle, than to constantly have little things spread out.