1994 Foretravel unihome check trans light

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1994 Foretravel unihome check trans light

July 15, 2024, 01:47:36 pm

Hello, I have a 1994 Foretravel unihome with a 6v90. The check transmission light is on the speedometer. Has been on for a couple of weeks. I have not noticed any issue with the transmission. I have checked the fluids. I've tried using the switches under the dash to read the codes. I did try the switches about a week ago and I got engine codes to flash but now I can't get anything to flash. Our gear shifter is different than most that I've seen online that can read out codes(I have attached a picture of the gear shifter). Any help would be greatly appreciated.

Re: 1994 Foretravel unihome check trans light

Reply #1 – July 15, 2024, 02:51:39 pm

Hello and Welcome to the Forum! We always appreciate hearing from new members.

That is indeed a less common transmission selector. It is fitted to the early model Allison ATEC transmission models. I did a brief Google search and came up with the two links below which may help you identify other possible sources of information. Unfortunately I did not find an online trouble shooting manual for that transmission model.

Allison ATEC Shift Selector 23045064 & 23048154 - Reman 6 Month Warranty | eBay

Do Not Shift Light Flashing Allison 748 ATEC

Re: 1994 Foretravel unihome check trans light

Reply #2 – July 15, 2024, 02:57:20 pm

The U300 with Detroit Diesel 6V92 is equipped with the hydraulic transmission-- the generation before the electronic 3000 and 4000 units.

That IS the OE shift pad.

If your research and diagnostics don't reveal the issue, you might contact John. I don't know whether he works on that series or not, but know he is the guru on the newer ones. If not, ask him for a recommendation of who to contact.

Transmission Instruments

Re: 1994 Foretravel unihome check trans light

Reply #3 – July 15, 2024, 03:05:49 pm

Thanks for the reply. The transmission shifter itself does not have a warning light on. It is just the warning light on the speedometer. The transmission drives and shifts through all of the gears.

Re: 1994 Foretravel unihome check trans light

Reply #4 – July 15, 2024, 04:54:01 pm

You may be fortunate - having a check trans light on dash BUT the transmission is still working. Seems the usual situation is that the trans won't shift.

Can't tell from your profile page where you are located. The thread linked below (Reply #22) identifies a shop in the Houston area that may be helpful.

1991 Grand Villa Check Trans Light is on

Re: 1994 Foretravel unihome check trans light

Reply #5 – July 15, 2024, 05:43:53 pm

That was my post about the check trans light

I end up fix it with cleaning the fuse to the atec transmission

See my detail post here
Fixing 91 U300 Allison MTB 648 Do Not Shift Light

It is an easy check, give it a try. I think likely yours is caused by same issue.

Re: 1994 Foretravel unihome check trans light

Reply #6 – July 15, 2024, 05:51:37 pm

When in Houston area and need Allison Tranny help, contact

Large Family Transmission Repair
281/844-6026

They are mobile and will come to you. Excellent work for a good number of folks I have referred.

Re: 1994 Foretravel unihome check trans light

Reply #7 – July 15, 2024, 06:04:05 pm

We are in Minnesota. I had a guy hook up his snap on heavy duty scanner and it could not find the ecm so maybe it is a battery issue like that other post. Or maybe he didn't have the ddec software on his scanner.

Re: 1994 Foretravel unihome check trans light

Reply #8 – July 15, 2024, 06:55:12 pm

Hello and welcome,, i had a similar issues with my 92 u 300 with the detroit. Ours came on while driving in heavy rain. I pulled over and did all the checks and found nothing. It stayed on for a couple more miles and went off.
When we got home i crawled under and checked the plug on the tranny and cleaned the cotact plugged it back in and never happened again. Not sure if that your problem but you might try that. Good luck.

Re: 1994 Foretravel unihome check trans light

Reply #9 – July 15, 2024, 08:40:11 pm

Quote from: Andy 2 – July 15, 2024, 06:55:12 pm

When we got home i crawled under and checked the plug on the tranny and cleaned the contact, plugged it back in and never happened again. Not sure if that your problem but you might try that. Good luck.

Absolutely the first (least expensive step is to clean and verify that the electrical connections are good.

These are some of the best electric connection cleaners: DeoxIT D-Series page with shop | CAIG

Re: 1994 Foretravel unihome check trans light

Reply #10 – July 16, 2024, 11:14:24 am

I will check the fuse and connector.

Does anyone know what module I would need to get for a pro link so that I can scan the transmission?

Re: 1994 Foretravel unihome check trans light

Reply #11 – July 16, 2024, 12:48:28 pm

There should be a switch under the dash for transmission troubleshooting. The top of the dash panel lifts up from the front edge. If you hold that switch, the check transmission light should flash out a code.

Quote

To retrieve codes without the ProLink (the installation must include a Check Transmission light): 1. Start the vehicle and run the engine at idle with the shift selector in neutral. 2. Place and hold the Electronic Control test switch in the on position. 3. The Check Transmission light will flash the most important diagnostic code if one is present (Example: flash-pause-flash-flash-flash indicates Code 13). NOTE: The Check Transmission light not will flash if no codes are present. There is no Code 25 for No Codes as in DDEC. To clear codes without the ProLink: 1. Turn the vehicle off. 2. Place the Electronic Control diagnostic test switch in the on position. 3. Restart the vehicle. 4. Make sure the park brake and service brake are applied, then shift from neutral to reverse, then back to neutral.

Attached page shows the codes

Re: 1994 Foretravel unihome check trans light

Reply #12 – July 17, 2024, 01:48:22 pm

So I have been trying the switches again to get codes. I got the engine codes to flash constantly now and I believe I know how they work. I am unable to get anything to flash for the transmission. Does that mean there is no codes?

I checked all of the transmission fuses under the dash pad and they look good.

I tried the clear codes procedure and the light stays on.

Re: 1994 Foretravel unihome check trans light

Reply #13 – July 17, 2024, 06:25:13 pm

Did you check the voltage of each side of the fuse?

Mine shows connectivity is good, but voltage drop from 13V to 9.2V below the tcm threshold

Quote from: FreightCreat – July 17, 2024, 01:48:22 pm

So I have been trying the switches again to get codes. I got the engine codes to flash constantly now and I believe I know how they work. I am unable to get anything to flash for the transmission. Does that mean there is no codes?

I checked all of the transmission fuses under the dash pad and they look good.

I tried the clear codes procedure and the light stays on.

Re: 1994 Foretravel unihome check trans light

Reply #14 – July 17, 2024, 09:06:34 pm

Quote from: Running Odometer – July 17, 2024, 06:25:13 pm

Did you check the voltage of each side of the fuse?

Mine shows connectivity is good, but voltage drop from 13V to 9.2V below the tcm threshold

I just checked the voltage and it is all good. I also pulled the fuses and checked for corrosion. The fuses and holders look clean.

I pulled the Atec computer fuse and started the coach. Once I started it the check trans light was on and the do not shift light was on. This is the first time I had the do not shift light on. But I put the fuse back in and the light went off so the Atec seems to be working then.

Could an engine code cause the trans light to come on? Could the transmission need an oil change? Does the transmission have an oil flow gauge?

Re: 1994 Foretravel unihome check trans light

Reply #15 – July 17, 2024, 09:52:03 pm

can you post a picture of the light?

Re: 1994 Foretravel unihome check trans light

Reply #16 – July 17, 2024, 10:18:56 pm

Here is a picture of the light.

Re: 1994 Foretravel unihome check trans light

Reply #17 – July 17, 2024, 11:19:39 pm

Is the below 12 VDC voltage showing on the gauge an accurate reading of: chassis batteries? fuse "out" to transmission?

Re: 1994 Foretravel unihome check trans light

Reply #18 – July 18, 2024, 12:14:30 am

Quote from: wolfe10 – July 17, 2024, 11:19:39 pm

Is the below 12 VDC voltage showing on the gauge an accurate reading of: chassis batteries? fuse "out" to transmission?

When I was testing the voltage at the fuses they were at 12 volts so I think the battery is ok.

Re: 1994 Foretravel unihome check trans light

Reply #19 – July 18, 2024, 03:40:57 am

Normal voltage running the engine is over 13. 13.2? Double check the battery?

Re: 1994 Foretravel unihome check trans light

Reply #20 – July 18, 2024, 12:50:37 pm

does it go out when the engine is running?

Re: 1994 Foretravel unihome check trans light

Reply #21 – July 18, 2024, 01:04:22 pm

Quote from: kgrover – July 18, 2024, 12:50:37 pm

does it go out when the engine is running?

It is always on.

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