How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Richard Your Own Question
Richard
Richard, Dodge Technician
Category: Dodge
Satisfied Customers: 4141
Experience:  Over 26 years of experience as lead tech and shop foreman.
18534624
Type Your Dodge Question Here...
Richard is online now
A new question is answered every 9 seconds

po code 891 came up on my van, how can i trouble shoot it.

Customer Question

po code 891 came up on my van, how can i trouble shoot it.
Submitted: 6 years ago.
Category: Dodge
Expert:  Richard replied 6 years ago.

Hello and welcome to Just Answer!

P0891 sets in the TCM when the TCM senses there is more than 3 volts on the transmission relay output wire when it hasn't energized the relay. This is usually caused by stuck contacts in the transmission relay. Would you be able to swap the EATX(transmission) relay with the horn relay and see if the horn blows steady when you swap the relay. The relays are located in the fuse box in the engine compartment.

Let me know and we can go from there!

Thank you,

Richard

Richard and other Dodge Specialists are ready to help you
Customer: replied 6 years ago.

yes sir, i tried that and the horn did not stick.

Expert:  Richard replied 6 years ago.

Can you erase the codes by disconnecting the battery negative cable for a minute and then see if the code or problem return? The relay can stick intermittently and I would like to know if the problem is still there.

Thank you,

Richard

Customer: replied 6 years ago.
copy that, sir, i will do. i'll let you know.
Expert:  Richard replied 6 years ago.

Thanks, XXXXX XXXXX know and I will get back to you asap!

 

Customer: replied 6 years ago.

ok, i did that, drove it around the block and it came back on. it is driving fine and shifting fine.

Expert:  Richard replied 6 years ago.

Can you see if it still has the same code?

 

Lets try this - Sit in the vehicle with all doors closed and starting with the key in the off position, turn it to ON, OFF, ON, OFF, ON (don't turn the key to the start position just on) within 5 seconds and leave the key on and watch the digital odometer to see if it displays a fault code. It will be a P followed by 4 numbers example P0700. When it is done displaying codes or if there are no codes it will say done. If you can't get this to work, please try it again following the instructions!

Customer: replied 6 years ago.
did that, said exactly that PO700 and done. Not sure what else i can try.
Expert:  Richard replied 6 years ago.

This means you either have a wiring problem or an internal PCM problem.

Do you have a digital multimeter and could do a few tests for me?

Customer: replied 6 years ago.
i don't, i called my local mechanic and have set up a time to have him take a look at it. thank you for all your help, you were extremely helpful.
Expert:  Richard replied 6 years ago.

You are very welcome!

Have a safe and happy holiday season and all the best to you in the new year!

Thank you,

Richard