scangauge codes for AIR and MAF?

[morninghill]

Have a 2004 W20 chassis, just got a scangauge. Have been able to set all the xgauges except AIR (ambient air temperature), and MAF (mass air flow).

Have tried both farenheit and celsius codes for ambient air for VPW vehicles from Linear Logic. No joy. The intake air gauge works fine.

I can't find anything for codes for Mass Air Flow.

Have tried search on this site and GOOGLE. More options?

Thanks
Mike

[oemtech]

The IAT is a standard gauge...

Mass Air Flow Sensor
TXD 686AF10110
RXF 044145100000
RXD 2810
MTH 000100010000
NAME MAF

[edgray]

Quote:

Originally Posted by oemtech The IAT is a standard gauge...

DALE: You are a tremendous resource for us all. Sometimes your posts are a little too cryptic for the uninformed (like me). so will you please confirm (elaborate) on what is meant by your comment I've quoted.

As always, THANK YOU for all you do here. ED

[oemtech]

The IAT is the "Internal Ambient Temperature" is sensor located in the MAF (Mass Air Flow - Ed) sensor and is use to tell the temp of the air going thru the MAF.

[edgray]

Dale: thanks for that additional info. So, does your original post mean that the IAT is displayed by the SGII as part of its "regular" gauge menu, and therfore does not need to be programmed as an Xguage? I'm just tryin to help the OP, OK?

[morninghill]

Thanks for the MAF codes, I'll add those tomorrow. I'm particularly interested in this as I drive a Trek, another Trek owner has had three failed engines, and Brazel's has indicated this is possibly because of MAF sensor problems.

The manual I got with my ScanGauge shows normal gauges include intake air temperature (temperature of the air entering the engine). I have this.

On the xgauge list of codes there is also a set of codes for ambient air temperature, they suggest the name be AIR. This is in the portion of the list titled "Standard Data". There is a note stating not all gauges are supported by all cars and your vehicle may not provide the data. I'm assuming this is the air temperature reported on most passenger cars, the actual outside temperature, rather than the intake air temperature of the engine. Perhaps the Workhorse chassis just doesn't include this sensor. AIR would be nice to have, but MAF is probably more important.

[DriVer]

The IAT was working on my X-Gauge SGII when Oemy mailed it to me.

[oemtech]

It looks like this is a standard PID for GM VPW protocol. It may not be a supported PID on our ECM's. I will try to check it out this w/e as we are heading to a RV club rally tomorrow.

[ron55]

how can a maf cause 3 failed engines? I was messing with mine and forgot to plug it in and drove it 1200 miles to florida before I discovered that.
I had a chevy pickup and switch the maf out with the workhorse and they both worked the same in either vehicle

[DriVer]

Quote:

Originally Posted by ron55 how can a maf cause 3 failed engines? I was messing with mine and forgot to plug it in and drove it 1200 miles to Florida before I discovered that.

OK, I'll take a whack at it!

If the MAF is disconnected, the ECM still polls the buss and if it's not present, the values required by the ECM from MAF go to a default value for data provided by the MAF.

If the MAF is present and its sending erroneous data, the ECM may accept those inputs to the detriment of the engine.

How's that?

It is very difficult to comprehend that a failed MAF ate 3 engines.

[morninghill]

Quote:

Originally Posted by ron55 how can a maf cause 3 failed engines? I was messing with mine and forgot to plug it in and drove it 1200 miles to florida before I discovered that. I had a chevy pickup and switch the maf out with the workhorse and they both worked the same in either vehicle

Have no idea why, not a mechanic. However, have no reason to doubt
Brazel's expertise. The unfortunate owner posted

"The head gasket went, allowing coolant to get into the engine, and causing damage to the bearings and other parts. A new engine was ordered by Workhorse, and has finally been installed.

Yesterday, the engine was running, and Brazel's put the Trek on the Dyno. Tests showed that the MAS airflow sensor was totally out of range. They were able to recreate the pinging that we have been experiencing, and found it to be extreme. They feel that the sensor was so far out of range and the pinging so extreme, that they concluded that the problems and blown engines were caused by this bad sensor."

May not be definitive, but good enough for me to be happy to monitor the MAF sensor. Now, if I just knew what to look for.

Moderators - not sure if quoting a post from another forum is approppriate. If a problem, let me know.

[M&EM]

Quote:

Originally Posted by morninghill Perhaps the Workhorse chassis just doesn't include this sensor. AIR would be nice to have, but MAF is probably more important.

My chassis has both outside air and IAT as indicated by the Actia menu and by the Autotap available OBD2 parameters. Both seem to work. The outside air may be function of what the coach builder orders from WH or simply a thermistor they plug into the wiring harness up front. My sensor is located on drivers side behind the grill area. Interestingly, both readings agree quite closely when on the highway and with a fairly good thottle opening such as climbing a hill.

Marty

[Fred and Bonnie]

I have a thought on 3 MAF failurers. Overoiled K&N air filter?

Fred

[CoastieSCPO]

When we were on our trip to Alaska this past summer, I felt the engine miss a couple of times when we were driving in wet weather. Then during a segment driving from Fairbanks to Tok, the engine light went on and the engine missed a couple of times. I pulled over, sat awhile and reset the computer, started the engine up and the light remained lit. We were in the boonies, no cell service so I decided to drive 85 miles or so to Tok. A mechanic there pulled the code which indicated a MAF Sensor problem. Three days later new MAf Sensor arrived and we were on our way. But, along the lines of what Fred suggested, my air filter, which had been oiled when I installed it, was filthy and had been affected by water from all the heavy rain. Later during the trip, when we got off the ferry in Prince Rupert there was more heavy rain and the engine missed again but when it was dry, no problem. Then during our final leg of the trip near home, the exhaust sounded like a Harley Davidson's and I noted more black soot than normal. At home, I pulled the plugs and installed the newer, hotter ones and put another new air filter in. She's running great now. Going to get the new cold air kit from Oemy when I have a few extra bucks. Gotta be better than the stock unit.

Bob