Technical 100hp Intermittent Power Steering issue.

[GaryJ79]

Hey guys,
I know this is a common issue, however no other thread has details the same as my problem .
OK, so my PAS light came on a couple of weeks ago and I thought I'd play it by ear as it was fine once I did a restart and didn't come back for 3 or so weeks. So the last few days it has started to fault more regularly. I hit the sport mode button as I know it changes the amount of power assistance and it hasn't faulted once in around 30 miles where as it faulted 3-4 times in the 20 miles prior. From what I have read the issue could be battery related as I have a little FM transmitter/USB charger which shows battery voltage when you plug it in. It can read as low as low 12.x and the highest I've ever seen it is 13.7. If I am doing a few short start/stop trips it shows low and higher after a 20 mile or so drive. Anyway to my limited knowledge I would assume that the alternator is doing it's job but the battery needs replacing and is likely getting worse with time and causing this PAS issue. I'm guessing with sport mode on it isn't as hard on the battery as the power assistance is less. Any advice or opinions welcome.
Tah..

 

[GaryJ79]

OK, so I was under the impression that a healthy battery should show 14.x volts but something I just read said different . Thoughts.

 

[koalar]

OK, so I was under the impression that a healthy battery should show 14.x volts but something I just read said different . Thoughts.

Depends where your measuring it
Some voltage drop is calculated into the cables, otherwise all the cables would be thick and heavy

On top of the battery normally measures 14.1V with no electrics on and at idle


Measured internal at the ECU there is about a 0.5V drop

A transmitter/USB charger which shows battery voltage will not show sudden voltage drops it's far too slow

 

[koalar]

Pretty much all covered here

EPS electric power steering faults | FIAT Panda (Mk3)

First don't panic, the vast majority of power steering faults are normally simple and cheap fixes especially if it starts failing mainly in your winter months But unfortunately nobody can say change this or do that and it fix it. A lot of different faults will cause the same symptoms or the...

www.fiatforum.com

There's no reliable test for the battery, even garages get it wrong

You don't say how old the battery is

The fact its better in sports mode points to a power issue, I'd start by substituting a known good one as its the most likely

Battery
Wiring
Alternator

 

[jrkitching]

OK, so I was under the impression that a healthy battery should show 14.x volts but something I just read said different . Thoughts.

Depending on the specific battery type, a fully charged disconnected lead-acid battery will be somewhere in the range 12.6V-12.9V when new.
With the battery connected and the engine running, expect to see a value in the 13.5V-14.5V range.

To get some idea of how worn the battery actually is, remove it from the car, charge fully, leave to stand for 24 hrs and measure the voltage. Now cross reference this measured voltage to a state of charge table for the specific type of battery you have. If it's less than 80% charged, the battery is probably scrap.

Even new batteries can lose up to 10% of their initial charge in the first 24 hours; the self discharge rate of a battery in good condition reduces considerably after that.

 

[GaryJ79]

Hey guys,
Really appreciate the feedback. I will look to do a few tests on the battery but will first need to buy a charger and a volt meter. Never bad things to add to the collection of tools. Not sure how old the battery is as I just bought the car 6-7 weeks ago. Looking at it, it doesn't seem overly old but it doesn't look overly new either.
Everyday's a school day when you own a car the guts of 15 years old lol. Thank God for people like you guys on owner forums and how to guides on YouTube!!
I love the wee car so it's a labour of love and all good fun until the bank balance takes a mightyfull hit.

Tah!

 

[koalar]

and a volt meter.

Post 5

About as cheap as you can go with current at the time I posted it and still be useful

Cheap Scanners Known to Work | FIAT Panda (Mk3)

I see a few people asking about engine check light I thread with readers known to work might help others I see someone has had success with a C reader 30001 Which also does live data 👍 https://www.fiatforum.com/threads/fiat-diesel-garage-in-the-midlands.496210/ and in 2022 can be had for...

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[GaryJ79]

About as cheap as you can go with current at the time I posted it and still be useful

Yeah, did a wee check on tgere earlier. I use Ali express for a lot of stuff. You can easily spend a lot of money on there on loads of little gadgets, nice nacs and cheap tools for the DIY'er.

Looking at prices it won't cost anymore than £15 for both. Couldn't beat it!!

 

[GaryJ79]

Ooh, you were talking about a scanner. I actually have 2. Haven't plugged them in as I was on the way to work the last time the fault poped up and didn't have any time to spare. Does the fault need to be active to get a code? Since I got them I actually haven't had any faults to look into and have 2 as I thought my first one was faulty but turned out to be the ODB port on my C2 Vts I had a couple of years ago. That was another great wee car until I crashed RRR. Was a pretty minor accident on a country road with some sort of farm spillage that made me lose it but a drainage ditch along the side of the road caused a lot of damage and I had to let it go. Was totally gutted as I really took care of it and it was a great example before that.

 

[koalar]

Ooh, you were talking about a scanner. I actually have 2. Haven't plugged them in as I was on the way to work the last time the fault poped up and didn't have any time to spare. Does the fault need to be active to get a code? Since I got them I actually haven't had any faults to look into and have 2 as I thought my first one was faulty but turned out to be the ODB port on my C2 Vts I had a couple of years ago. That was another great wee car until I crashed RRR. Was a pretty minor accident on a country road with some sort of farm spillage that made me lose it but a drainage ditch along the side of the road caused a lot of damage and I had to let it go. Was totally gutted as I really took care of it and it was a great example before that.

No post 5 is a £6 multi meter that also measures amps, it's pretty fast also

Wouldn't want to use it at high volts though

Normally a waste of time reading the codes, and misleading even if you can access the steering module

If voltage is low to the torque sensor it reports it back as faulty because is sending incorrect or unexpected data, it could also be faulty. So it's inconclusive

The only good news is if the error code is power the fault is power but it will not tell you if it's battery, alternator or wiring

Due to the nature of the fault is almost certainly power relative battery, alternator or wiring, I have had several failures of electric power steering in fiat, Mercedes and vauxhall, all bar one was the battery, the other was a slipping alternator belt

There's more to a battery than its charge, internal resistance is just as important

I know of no cheap reliable , battery checker or so on that can 100% sort this out. Take a look at some of the previous posts some go on for over a year with several garages test their battery okay for it to be the battery in the end

Some else has had two refurbished steering columns for it to be the battery

People often check the battery and it is fine and then end up going down many blind allies because the battery had falsely checked okay

I am lucking in having two cars, I just swap the batteries over

Without spending nearly a grand on the same battery checker fiat use there isn't a simple 100% check

You can get lucky, maybe if you check the resting voltage and it's not holding a charge then you might be on a winner

However those charts are only good for one particular make, model, capacity and temperature of battery although they are in the ball park

Substitution for known good is the only 100% way for the home mechanic

Put it on charge over night and there is an improvement is the next best thing

We need to get the most likely out of the way first, so we can move on to the next set of tests.

Multi meter is a must have if you are dealing with older cars and also useful around the house for checking switches, fuses ect. In my opinion

 

[koalar]

The date code is normally on the battery

B9. Would be February 1999 as would 9B

Sometimes on the side is melted the date of when it's first charge is due if its being stored

Surprising how often we see ESP problems on cars recently purchased, I suspect they end up being stood awhile prior to the decision to sell

 

[DaveMcT]

My 100Hp has a cheap voltmeter on the old cigar lighter wiring. It's useful for showing the voltage trend but never shows more than 13.8V. The alternator was replaced due to the casing cracking and starting to seize up. Indicated voltage was unchanged with the new one.

A 100% full (flood charged) lead acid will show 12.9 volts for a very short time but that quickly drops to 12.6 - the normal fully charged value. It's normal behaviour. Conditioning chargers (eg Opitmate) keep the battery full without electrolysing the water.

I have a Yuasa YBX5012. My wife's 1.2 has a HSB012 both are basically the same but do the job extremely well. Both bought from Tanya batteries.

YBX5012 Yuasa Silver High Performance Car Battery 12V 54Ah HSB012

YBX5012 Yuasa Silver High Performance Car Battery 12V HSB012 Advanced Engineering, Premium Quality, Unmatched Reliability GS Yuasa located in Japan, all started in 1895 and is one of the biggest battery manufacturers in the world. Manufacturing batteries for the automotive, commercial and...

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It's summer, so use the car normally. If the problem gets worse replace the battery. If the car was bought recently, it's probably because the battery stood unused for too long. Lead acid hates that and will degrade. I test mine with an Optimate charger. If it's indicating flat (not turning the engine properly etc) charge with the opitmate. If it takes all night or more the battery is probably good but discharged. A flat battery that fills full after a couple of hours, has minimal capacity, so should be replaced.

If you are interested there's lots of stuff here

BU-403: Charging Lead Acid

BU meta description needed...

batteryuniversity.com