Hi everyone

 

I have accidently performed a reverse polarity jump start on my 2014 ford fiesta 1.0 ecoboost and the car is now not starting.

I checked all of the fuses and relays and had to replace only one fuse.

Instrument lights come on but there is no cranking at all.

I also checked the big fuses on the positive battery connection which are all fine.

I am hoping that the ecu may be okay but am considering in trying ecu doctor to check and maybe repair it if ia faulty.

Has anyone got any experience or knowledge as to what else to test before sending the ecu off ?

Thank you

Which fuse blew?

Try to read fault codes to see if all modules are active/on line - if you can't communicate with one or more, they may be faulty?

Check CAN  wires for resistance (you'll need to find out how from You Tube ) and voltages to try to see if it is behaving normally.

Test starter motor directly if everything else is OK - you state instrument lights come on but nothing else - when you try to start does anything at all happen?

Remember, I'm just guessing as you don't have ANY  evidence other than the fuses you have checked - there may be more to check?

The OP has already got a thread open where he's given some more details of what happened.

 

1 hour ago, Shearers said:

Which fuse blew?

Try to read fault codes to see if all modules are active/on line - if you can't communicate with one or more, they may be faulty?

Check CAN  wires for resistance (you'll need to find out how from You Tube ) and voltages to try to see if it is behaving normally.

Test starter motor directly if everything else is OK - you state instrument lights come on but nothing else - when you try to start does anything at all happen?

Remember, I'm just guessing as you don't have ANY  evidence other than the fuses you have checked - there may be more to check?

There was only one code which was about throttle body.

 

Okay I will look into the can wires and starter directly thank you.

When I try to start nothing happends just some clicking sound coming from the inside fuse box.

 

Yes checked fuses and relays and not sure what else to check.

 

Thank you for your kind help and support with this.

 

56 minutes ago, nicam49 said:

The OP has already got a thread open where he's given some more details of what happened.

 

Thank you for sharing this, the only reason why I started a new thread as I now know the correct term for the mistake and titled it accordingly to hopefully get more specific help with this.

🙏🏽

I have suggested (in the other thread) that it should be locked and further discussion continued here (but I'm not a Mod so can't do it)

What a dilemma to be in esp at this time of year. If you've got a multimeter, then at least you can do a CAN bus test and see if you're getting the correct resistance on it, then go from there...but if you're getting clicking from the fusebox, try and locate which relay it is causing it.

2 hours ago, nicam49 said:

What a dilemma to be in esp at this time of year. If you've got a multimeter, then at least you can do a CAN bus test and see if you're getting the correct resistance on it, then go from there...but if you're getting clicking from the fusebox, try and locate which relay it is causing it.

yes worst time to be getting this problem now

 I may try a can bus test then, has anyone got a diagram of the obd port to carry out this test ?

I might also test the starter motor with a multimeter.

Someone suggested for me to check the big 100 fuse near the battery, is that the one that sits on the positive battery conection or is that somewhere else ?

There's a pinout pic somewhere on here...I'll try to locate it unless another forum member can get there 1st!

This is of no help to you but be thankful.

Some years ago the coach alonside of me had a flat battery and would not start. Batteries for a coach are enormous and fitted in pairs.

The fitter came along with a big heavy jump start trolley thing and connected it up. moments later there was a resounding explosion as the top of the two coach batteries blew off spraying acid everywhere.

At a minimum the fitter was in for some retraining about connecting up for a jump start.

ScaniaPBman.

25 minutes ago, ScaniaPBman said:

This is of no help to you but be thankful.

Some years ago the coach alonside of me had a flat battery and would not start. Batteries for a coach are enormous and fitted in pairs.

The fitter came along with a big heavy jump start trolley thing and connected it up. moments later there was a resounding explosion as the top of the two coach batteries blew off spraying acid everywhere.

At a minimum the fitter was in for some retraining about connecting up for a jump start.

ScaniaPBman.

let's hope no one got injured which is what matters most.

11 hours ago, wali110 said:

is that the one that sits on the positive battery conection or is that somewhere else ?

Yes, have a look under the positive connection to see any are broken.

 

We know it can't be the main fuse if you're still getting dash lights.

This seems to step you through CAN  issues if the starter appears sound (first need to test that solenoid is getting a signal, or bypass the small lead?):

 

On 4/11/2024 at 8:54 PM, unofix said:

Yes, pretty much so. There is one 120 Ohm resistor fitted across each pair of canbus wires at the start and finish of the network. So in effect two 120 resistors are fitted in parallel. If there is a break in the wiring then you will only read across one of the resistors which would give a value of 120 instead of 60 Ohms.

 

22 hours ago, TomsFocus said:

Yes, have a look under the positive connection to see any are broken.

 

We know it can't be the main fuse if you're still getting dash lights.

I already checked them but thanks anyways

22 hours ago, Shearers said:

This seems to step you through CAN  issues if the starter appears sound (first need to test that solenoid is getting a signal, or bypass the small lead?):

 

thank you, and the best way to test the starter would be to turn the ignition on and then check the positive and negative on the solenoid with a multimeter to get a reading or at least 12v ?

22 hours ago, unofix said:

 

That is perfect, thank you so much for that 🙏🏽

Hi again

I have not yet managed to test the starter but will try tomorrow.

I have however just done a CAN BUS Test and got the following readings:

HS Bus: 62.1

MS Bus: 53.2

MM Bus: no reading

I also hooked up my Forscan tool and got the following code:

U0164 - Lost communication with HVAC Control Module 'A'.

As well as : 

P2123 - Throttle/Pedal Position Sensor/Switch 'D' Circuit High

P0562 - Battery Voltage Low 

The Battery Voltage is at around 12.2V while I performed the test and have now hooked up my Battery Charger to the Battery.

I presume that there may be some problem with either one of the Modules or the Bus itself but not really certain ?

I suppose the above test may have confirmed a fault with my ECU but not certain ?

If that is the case then is there any point in still having to test my Starter ?

I would be grateful if someone with a better understanding of the test results can let me know what may be damaged.

 

Thank you again for all the help and support I have been getting, I really appreciate it 🙏🏽

18 minutes ago, wali110 said:

MM Bus: no reading

I don't think your car has a MM Can Bus. When you connect FORScan what Bus each Module is on is shown in the Profile under each Module.

With respect to the Fault Codes, they may be historical ones. Try to clear them and see if they come back.

 

1 hour ago, Tizer said:

I don't think your car has a MM Can Bus. When you connect FORScan what Bus each Module is on is shown in the Profile under each Module.

With respect to the Fault Codes, they may be historical ones. Try to clear them and see if they come back.

 

ah okay that is reassuring thank you.

 

Do you know how I can access the Modules in Forscan ?

Thanks again

On 12/25/2024 at 11:41 AM, unofix said:

 

would you maybe know what the fault may be or what I could try next ?

42 minutes ago, wali110 said:

Do you know how I can access the Modules in Forscan ?

When you open FORScan all the Modules are shown in the Profile that pops up. If you connect again, when it asks you if you want to use the stored Profile say no but save it and let FORScan create a new Profile. Compare it to the saved Profile, if any of the Modules are dead then they will not show up.

If they do show up then that is a good thing but it does not mean that they are working ok.

I don't know what is causing the fault. There is sometimes a high Amperage Mega Fuse in the Wiring Loom to the Alternator, but I'm not sure if that being blown would cause your fault, even if your car has one, I don't know if your car has one or not.

13 hours ago, wali110 said:

would you maybe know what the fault may be or what I could try next ?

Do as John says and clear all the DTC's and see what comes back. The starter motor can not be at fault due to trying to reverse polarity jump start the car. The starter solenoid would not have operated and the starter motor would not be 'in circuit' so could not have been damaged.

The canbus resistance reading look OK, and your model does not have a MM canbus so no need to worry about that. Get the battery fully charged for a minimum of 12 hours before continuing to fault find.

Totally agree with the above.

There is still some doubt about any damage due to applying the jump starter in reverse.

The main problem at the moment seems to me to be the fact that the starter isn't turning so getting that to work first (by checking circuit,  bypassing the switch/relay etc) to see if it will turn over and perhaps start may be a priority.

Definitely need to keep battery fully charged during all of this.

If, after getting some cranking, it won't start then checking any fault codes (and being certain that PCM is online and producing any relevant codes) would be my next step (see disclaimer below of course!)

As usual, we are hamstrung by the lack of freely available (or at reasonable cost) wiring diagrams? Haynes Autofix is a source I have but the diagrams are not easy to follow.

15 hours ago, Tizer said:

When you open FORScan all the Modules are shown in the Profile that pops up. If you connect again, when it asks you if you want to use the stored Profile say no but save it and let FORScan create a new Profile. Compare it to the saved Profile, if any of the Modules are dead then they will not show up.

If they do show up then that is a good thing but it does not mean that they are working ok.

I don't know what is causing the fault. There is sometimes a high Amperage Mega Fuse in the Wiring Loom to the Alternator, but I'm not sure if that being blown would cause your fault, even if your car has one, I don't know if your car has one or not.

Thank you both of your with your help with this.

 

I have had the Battery charged for around 6 Hours with the charger which showed a light saying the Battery was fully charged, checked the Voltage myself and it came back as 12.3V.

I performed another CAN Bus test and both readings came back between 60-62 which should be good.

I then went to connect FORScan using a new Profile and it came back with: PCM: unable to read dtc

I decided to reset the dtc and it then managed to read the dtc

I then first performed a Battery Voltage Test which came back good I believe.

The Fault codes that stayed on after having cleared them was the Throttle one (that I also saw some weeks ago while the Car was running) and the Batter Voltage one:

P2123 - Throttle/Pedal Position Sensor/Switch 'D' Circuit High

P0562 - Battery Voltage Low 

I then tried to check some of the Modules but not sure how to, I only have the free Version of FORScan which may not allow for me to check them.

I did manage to perform some other check of which I will post the screenshots on here.

As I was sitting in the Car with the Laptop connected and the Instrument Lights on did I notice the Battery had started to drop.

A little more background information:

My Car had previously been parked up for a few weeks and I had to get the Battery jump started almost every every trip.

I decided to buy a Battery charger instead of replacing the Battery which seemed to have fixed the problem on the first and second start.

I then performed a Parasitic draw test at the Battery negative Terminal which showed no draw and after reconnecting the Lead was the Battery Flat again. I was at work at the time and in a rush and accidently performed the reverse polarity jump start.

I will now reconnect the charger and may just leave it connected while performing the checks this time and will also try to test the Starter Motor and see if I can find a mega fuse.

Thank you all for your help once again I really appreciate it.