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 Pete Your Own Question
Pete
Pete, Technician
Category: Car
Satisfied Customers: 26710
Experience:  17 years automotive training and experience.
14928985
Type Your Car Question Here...
Pete is online now
A new question is answered every 9 seconds

I have a p0653 code. Ive been told thats its likely

This answer was rated:

I have a p0653 code. I've been told that's it's likely to be a ecu fault, does this sound right? Thanks.

Hi Gareth,

 

My name is XXXXX XXXXX I am a professional here at Just Answer. I noticed that your question was not getting a response and thought I would ask to see if you still need help with this.

If the alternator was outputting high voltage like this here it is possible that this has damaged the ecm itself as I have seen voltage surge/spikes will cause an issue like this here.Usually you would see more then the 4.9 volts for voltage with this code but if the ecm is internally spiking intermittently and is damaged it can cause this.I would double check all 5 volt references to make sure none are shorted to voltage anywhere before replacing the ecm.

Make sure you have no faulty or damaged wiring,make sure the electrical connections on the engine are tight as well.

I hope this has helped in some way here.If you need anything else don't hesitate to ask thats what I am here for.If you are not satisfied with my help here let me know before rating my help.

Thanks Pete

Customer: replied 4 years ago.

hi mate


thanks for the reply


i have only checked the reference voltage at the MAF plug and at the MAP plug, I assumed there is only one reference line that is common to all sensors?


Ive checked as much as i can for wiring damage etc.


Initially i had this fault after the van had been sat for a period of time and the battery died. I fitted a new battery, started it up and immediately had fault lights and limp mode.

Have the codes been reset/erased to see if they come back again?
Customer: replied 4 years ago.

yes there was several undervoltage type faults which all reset, then i was just left with this fault which would not reset.

If your vehicle only has one battery in it try disconnecting the battery cables and touching the two cables together (with battery out of the picture) as this will discharge the capacitors in the computer to reset it,hold them like this for about 1 minute(your radio may need a security code when this is done which this would need to be reset by the dealer).In some cases this may reset this type of fault if the voltage issue from the alternator had caused this.

If this does not work it is possible since the 5 volt reference is o.k. that the ecm itself may be at fault here.

I hope this has helped in some way here.If you need anything else don't hesitate to ask thats what I am here for.If you are not satisfied with my help here let me know before rating my help.

Thanks Pete
Customer: replied 4 years ago.


I have tried the battery trick before, but I will try it again. It does seem like it is an ecu fault, I just wanted to be sure really.


Thanks very much for your help.


 


One last thing, if I were to get a new ecu from VW would it come ready to plug and play? or would it need to be coded with a laptop?

Usually it has to be setup/programmed to the vehicle using the dealers tool so if it is replaced it may be best for them to replace it so this can be done.I hope you can get this resolved with ease,let me know if you need anything else in the future.Thanks Pete
Pete and 7 other Car Specialists are ready to help you
Hi,

I am following up with you to see if you still needed help with your question you had asked.If my help didn't satisfy your question please let me know so we can continue.

Thanks Pete