BAWC Forums

Jeff V. wrote: ↑Wed Jan 11, 2023 5:55 pm What does the MAF have to do with this?

I have no idea

Maybe GM uses MAF inputs to help control the transmission as well as idle etc

Chris GTO TT wrote: ↑Wed Jan 11, 2023 6:43 pm Maybe GM uses MAF inputs to help control the transmission as well as idle etc

I mean the MAF on the H3 Alpha sits about as high up as it can in the engine bay. Not sure how moving it would help

Im maffled by your response to the transmission issues.

Chris GTO TT wrote: ↑Wed Jan 11, 2023 6:43 pm Maybe GM uses MAF inputs to help control the transmission as well as idle etc

That's a bingo.



I mean it's just a shot in the dark without seeing any readings.

It did feel kind of like the AF was all messed up. Like it was kind of choked off.

Vira got me an UltraGauge for Christmas. https://www.ultra-gauge.com/ultragauge/

I'll have to reconfigure it to show MAF readings. It's nice once you have it set up, but damn is it painful to get there. It's only got 3 buttons on the back. Select, up and down. No USB setup, no SD card, just paging up and down through tedious little menus. That's on me for not doing my homework better though.

Don't you have a tech 2?

Sort of. I've got a bootleg version of the GM Tech2 emulator. I'll check it with that first. But going forward it might not be a bad idea to have that number up on the dash.

I know one of the first things for the avalanche is to clean the connectors that go to the maf and spray some cleaner in the maf. Just saying don’t count it out.

Coop

My silverado needed a new maf. After some issues I was having a new maf cleared it right up

I think it might be ok. I had to go through a hassle getting my bootleg Tech2 software working again, but when I did I found a bunch of data bus errors. I'm pretty sure it was that UltraGauge.

Last night when I came in the house, I noticed it wasn't turning off. So I went out and unplugged it from the OBD2 port. I plugged it back in this morning when I started the truck. That may have caused a jolt on the data bus and got the ECM and TCM out of sync. I think you're supposed to wait for it to do its initial auto scan before you turn the key.

Anyway, it was fine on a short test drive tonight. We'll see how it does tomorrow after a cold soak. I let it run for about 30 minutes while I was screwing around with the software, so it was fully up to temp when I went for the test drive.

It was totally fine on the way in to work today.

At least it was a simple fix.


Coop

Good deal.

Surprising that a gauge caused that.

When you first power up the UltraGauge, it does a scan of the bus to see what kind of vehicle it's connected to. It uses the OBD port for keepalive voltage, so it doesn't do this scan on subsequent startups. I don't know how aggressive that scan gets, but apparently it was enough to cause a bus off condition during start up and force the modules into limp mode. You're supposed to do a key on, scan, then start the engine. But it was early and I was tired and I wasn't thinking.

Jeff V. wrote: ↑Thu Jan 12, 2023 7:16 pm When you first power up the UltraGauge, it does a scan of the bus to see what kind of vehicle it's connected to. It uses the OBD port for keepalive voltage, so it doesn't do this scan on subsequent startups. I don't know how aggressive that scan gets, but apparently it was enough to cause a bus off condition during start up and force the modules into limp mode. You're supposed to do a key on, scan, then start the engine. But it was early and I was tired and I wasn't thinking.

You only need to do the scan the first time you hook it up?

Any time it does a power-off start up. Since I had unplugged it the night before, it was a new start when I plugged it back in the next morning. It's weird. It keeps your user settings like custom gauges, when power is removed. So clearly it has some kind of non-volatile memory. But it still insists on doing an auto scan every time you restart it.

It's a nice product, but it's got a lot of rough edges. For $80, I'm not complaining too much. I'm clearly not even trying to do anything better.

I'm trying to remember if I've ever actually parked this thing next to a stock H3 before now. I didn't realize the height difference was so significant.

Quit. You’re going to give others a complex.

The guy caught me on his way out of the store. Gave me a funny look.