Check engine light just came on

I left Disney World headed north in my 94 Class A Damon Challenger and my check engine light came on. When it did the engine felt like it shifted into neutral and it the engine revved up a bit then the light went off and it drove like normal. This kept happening about every 15 seconds or so. I was in a construction zone when this happened and there was no where to pull off. Finally I got out of the construction zone and pulled into a gas station safely and called CoachNet. They will be calling me back in a few minutes to tell me if they are going to tow me or send out a mechanic. Does anyone have a clue as to what is wrong? It ran real well all the way out here and got good mileage. Speaking of mileage, it has 67000 on the odometer. It is a Workhorse chassis with a 454.

Humm.... 1994, likely OBD 2, (I know 1994 cars were OBD2) but if it's OBD-1, (1992's were OBD-1) then you can read out the codes with a paper clip. that might help. to figure it out, and no, short of a shop manual, I do not know how to tell one from the other.

Does the gas station have a code reader (are they full service) or you can get one (Several to choose from) at Pep Boys, O'Riley's, Auto-Zone, et-al.

My 1995  454 Bago had an OBD 1.  (pobably an 1994 engine). 

  Google "how to read OBD1 without a meter". Lots of info there.  OBD1 connector is a multipin unit only pins 1 and 2 are used for reading manually. (Paperclip and count flashes on dash (Engine check light)

Low fluid in the transmission would be the first thing I would check.  Next would to check if there is an electrical connection to the transmission, and check it for tightness and corrosion.

Paul

It is definitely OBD1. I checked that out right after I bought it. If it would have been OBD2 I would have bought the reader. I wasn't really in a gas station, it was a 7/11 with pumps. I have been towed to a garage in Kissimmee and they are going to check it out in the morning. I did just check the trans fluid about 2000 miles ago and it was fine. I checked it this afternoon and it was down about a half a quart but that was after it had sat for an hour and the engine had cooled off a bit. The electrical connection having corrosion seems the most likely suspect at this point. I hope that is the problem since that would be about the cheapest repair. If they tell me I need a new tranny I am up a creek.

I have owned it a year and the tranny was the best thing about the RV. Shifted as smooth as butter. I always drive with the cruise control on at 55. I have not gone up any major grade and have done very little mountain driving. I haven't been over 4500 feet. I baby this thing so I am very surprised to have the tranny acting up.

Hope they can get you back on the road at minamil cost.
Bill

Many auto parts stores have OBD-1 & OBD-2 code readers and will read for free.

Tom, have you pulled the codes yet? Might give some indication of the problem.

Let me know what is going on and if there is anything I can help with.

Steve

Thank you for your kind offer Steve, I will keep you in mind.

I don't have any way to view the codes. The mechanic should be able to figure it out in the morning.

It's obd1 for sure. Have you located the dianostic port yet?  The top 2 on the right side of the plug is A B. Short those 2 with a paper clip. It will flash a code 12 three times before it flashs thr problem codes. It will flash the problem codes 3 times before it flashes the next. When finished with the problem codes it will go back to the code 12. Make sure the gas cap is tight. If the seal is leaking it'll throw a code. If it went back out it's probaby a o2 sensor.


Take a look at this link.

http://www.obd2allinone.com/sc/toplevel.asp?cat=2

http://www.gmtuners.com/OBD1_DTC.htm

I did check the gas cap and it was tight. That was one of the things I found when I Googled "check engine soon 454" while I was waiting for the tow truck.

The mechanic just put the OBD1 reader on it and there are no faults. He checked the tranny fluid and it is low. I guess I messed up reading the fluid level. He is putting fluid in right now. This should be interesting.

We have our fingers crossed for you! The chevy tranny is a pretty tough beast and hard to kill with any luck its a lesson learned and you will be on your way!!

Thank you Mike. I didn't drive it very far after it started acting up so I don't think I damaged anything. You are right, the 400 is a really tough tranny, that is why it is used in so many motorhomes.

Surprised you have a TH400, I would have thought it was an allison or a 480LE. Love those TH400's, easiest automatic tranny to rebuild.

Easy to rebuild when they need it. Those things where one of GMs better Ideas..

Just a nit pick but it might help save some confusion down the road - that is a Chevy chassis not a Workhorse.

Clay L said:

Just a nit pick but it might help save some confusion down the road - that is a Chevy chassis not a Workhorse.

Click to expand...

Thanks, I thought they were one and the same.

Nope, when I was trying to get some info on mine, I contacted workhorse and they didn't buy the chassis untill 99. Chevrolet didn't have any info, because they are too old. I ended up buying a chassis and electrical books on line for a motor home chassis. I also bought a scanner off of E-bay so I can work on my own. There is some differences between a MH and truck. There are many things that could have caused the check engine light to come on, but he should have been able to get a history code from the pcm. What did you find out?

The mechanics found out that the tranny fluid was low. So they added two quarts. The fluid in the tranny was a light brown color with no smell and no grit. After the fluid was added the tranny works fine without going out of gear and revving. The mechanic took it for a short test drive and called it fixed. $83.

However there is still a problem. Now it gets weird. When I push on the brake pedal about half way the "check engine soon" light comes on. I release the brake and the light goes off. Even weirder is at a stop sign pushing th brake doesn't cause the light to come on. Even weirder still is that when the light come on the speedometer start pulsing back and forth. So how is the warning light, the brakes and the speedometer connected? And even weirder yet, why did this problem occur after the low transmission fluid was causing the engine to rev up and the light to come on?

I am not in great financial shape after two weeks at Disney World and payday is a week away. So I mentioned this to Catblaster (Will) who lives in Kissimmee and he insisted I spend the week at his place in his front yard. Then he took me out to breakfast. While we were dining CaptSteve calls me and I give him a progress report. He says the problem is caused by a vacuum leak. I never knew speedometers used vacuum. I thought they were powered by a cable.

It is so wonderful being connected to this forum. We sure have some wonderful people on board. Will and Steve are just simply fantastic.