Code P1684

Problem solved, I kept on looking for causes when I finally found what the trouble I had was. Turned out it was an axle that broke at the joint, but the part that connects in the transmission, hence the mileage reading I was getting when I shifted in reverse or drive. It's the first time I see an axle break on that end instead of the other but still that's where the problem was. :-)

Hi Danny,

It happens to be a combination of troubles that I have with my caravan. Turns out I was right about the axle but after I put another one on it kept on doing the same thing it did in the beginning. So after multiple checks I found out the gears in my transmission are done for, so now I need to put in a new transmission and since I don't know how to repair this one because I've never opened a transmission before and I'm afraid that if I try that I'll make it worse than it already is, I'd rather just spend some money and get a new one and put it in.

Hello Danny,

Let me try to explain in details the exact problem I have with my transmission, then maybe you will be able to guide me in what kind of repair I need to do.

When my engine is running idle, my odometer that indicates how many kilometers I did since the last gas refill keeps on advancing and the transmission is on park position. If I put my transmission on reverse or drive and keep my foot on the brake pedal my speedometer automatically goes to 30 KM/H (about 24 MPH). If I let go of the brake pedal my right wheel will turn and when I apply speed (with whole front in the air) I hear some kind of a funny noise coming from under the van where the axle plugs in the transmission. So before I spend money on a new transmission I'd like to know what other tests I can do to try to solve my problem.

Thank you

Hello Danny.

Here's the video you requested, hope it works and you see it good. If you need more information let me know.

Thank you.

By the way sorry about the video quality, I'm not an expert in filming. I just reviewed the video after I uploaded it and I made it badly. I hope you still can see good.

I thought about the speed sensor as well, and some people even told me about the transmission solenoid. As for the alternator it's a brand new one that I put in a year ago.
Thanks for the tip. :-)

Hello Danny,

Yes, my whole front is presently jacked up in the air. I had to in order to replace the TCM and my right CV axle. Now as for the rotation only the right wheel turns, but I haven't noticed if the left one does as well.

Thank you.

Sorry I forgot part of your question. The TCM I replaced come from another caravan I picked up in a scrap yard, otherwise I would have had to pay $678 for one from dealer. As for the odometer, it does continue to advance (so to speak) when the transmission is engaged.

Thank you again

Hello Danny.

I just went to confirm the question you were asking me and yes, both the trip and odo meters keep on advancing when engine idles. On top of that my check engine turned on while making the verifications. One is P1684 which is the TCM code and the other one is P0456. Hope this can help you in the diagnosis.

Thank you

Hello Danny.

I got another comment from Al 514 about having my alternator checked because it may be at fault as well. The diodes in it may cause some kind of a power surge that makes my speedometer go bezerk. So I looked into the matter, made more researches on internet and tested something on my vehicle. When I get the engine started there's a funny whining kind of noise that I hear in the engine. So I disconnected a simple wire on the alternator and the noise stopped. So I'll start by removing the alternator and have it checked by a mechanic that is better equipped than I am to do that test. Is it normal that I can have a failing alternator even if it's a year old? I replaced it in January of 2019! Now here's a question: is it safe for me to try driving my van to bring it to a mechanic to have a scanner plugged in to take care of the trouble codes I mentioned?

Thank you.

Hello,

Here's a quick update on my trouble I had with my van: I got busy and didn't have the time to post an update on the progress I had made on my repairs. So after removing the alternator on my van I took it to mt mechanic that tested it and it was the diodes in it that were done for. So I had it fixed and then I put it back on my van and since everything is going good. I have no more issues whatsoever regarding that problem. I'd like to thank you Danny for trying to help me out as well as Al 514 for his idea of making me having my alternator checked. If I have issues with another mechanic job I'll be sure to come on this site and have a chat with you guys to help me out.