Keyless entry and start not working

[ericmcn]

I'd be surprised if it needed an AGM battery if it's not the ISG/START STOP model. I'd also expect the main dealers to have highlighted if the battery voltage was low. Do you happen to have a multimeter so you could check the voltage yourself?

A DVM wont tell the full story, you need a load tester.

A 20 second google found this, i would get a new battery as the one in the photo is no where near this spec, these are all 95Ah- assuming its not the 74-77Ah Type that is used (it seems to have two variants)

Hyundai ix35 - diesel engines:
2.0 CRDi (184 KM)

BRAND AND SERIES MODEL CAPACITY COLD CRANKING AMPS DIMENSIONS BASE HOLD-DOWN PRICE
Bosch S4 S40 28 95 Ah 830 A 306x173x225 mm B01 More
Exide Premium EA954 95 Ah 800 A 306x173x222 mm Korean B1 More
Exide Excell EB954 95 Ah 720 A 306x173x222 mm Korean B1 More
Varta Blue Dynamic G7 95 Ah 830 A 306x173x225 mm B01 More
These diesel engines should work with batteries of dimensions 306x173x222 mm or 306x173x225 mm, which capacity is minimum 92 Ah. The most basic battery of this set is Exide Excell EB954 of a capacity 95Ah and 720A Cold Cranking Amps, the battery with the biggest capacity is Varta Blue Dynamic G7 of a capacity 95 Ah, having 830A Cold Cranking Amps.

 

[Meatball]

A DVM wont tell the full story, you need a load tester.

A 20 second google found this, i would get a new battery as the one in the photo is no where near this spec, these are all 95Ah- assuming its not the 74-77Ah Type that is used (it seems to have two variants)

Hyundai ix35 - diesel engines:
2.0 CRDi (184 KM)

BRAND AND SERIES MODEL CAPACITY COLD CRANKING AMPS DIMENSIONS BASE HOLD-DOWN PRICE
Bosch S4 S40 28 95 Ah 830 A 306x173x225 mm B01 More
Exide Premium EA954 95 Ah 800 A 306x173x222 mm Korean B1 More
Exide Excell EB954 95 Ah 720 A 306x173x222 mm Korean B1 More
Varta Blue Dynamic G7 95 Ah 830 A 306x173x225 mm B01 More
These diesel engines should work with batteries of dimensions 306x173x222 mm or 306x173x225 mm, which capacity is minimum 92 Ah. The most basic battery of this set is Exide Excell EB954 of a capacity 95Ah and 720A Cold Cranking Amps, the battery with the biggest capacity is Varta Blue Dynamic G7 of a capacity 95 Ah, having 830A Cold Cranking Amps.

I’ll look into this, thanks for your help. I’ve asked a friend who works for Hyundai what the right battery spec should be.
Update: OEM battery rated at 90Ah


I phoned the garage director today. He seems willing to compensate me financially for the faulty keyless but I said ideally I want the functionality working. He’s willing to take it in for diagnostics but we just need to sort out the logistics regarding a courtesy car.

If it is the battery, although I’m not hopeful, it’ll make things much easier. It would just seem strange that Hyundai wouldn’t notice this and the system would pass their diagnostic tests if the battery wasn’t sufficient.

 

[ericmcn]

I’ll look into this, thanks for your help. I’ve asked a friend who works for Hyundai what the right battery spec should be.
Update: OEM battery rated at 90Ah


I phoned the garage director today. He seems willing to compensate me financially for the faulty keyless but I said ideally I want the functionality working. He’s willing to take it in for diagnostics but we just need to sort out the logistics regarding a courtesy car.

If it is the battery, although I’m not hopeful, it’ll make things much easier. It would just seem strange that Hyundai wouldn’t notice this and the system would pass their diagnostic tests if the battery wasn’t sufficient.

I don't mean to be rude but you need a new battery, your battery is no where near the rated performance. A diagnostic scanner in most cases wont tell the difference either.

So at the risk of repeating myself just get a battery - The garage, i don't think they have a clue

I would get a battery like this and no more faffing around, its OEM rated for 90Ah but you can use a 95Ah battery just fine

Bosch S4 S40 28 95 Ah 830 A 306x173x225 mm

 

[dale1uk]

I don't mean to be rude but you need a new battery, your battery is no where near the rated performance. A diagnostic scanner in most cases wont tell the difference either.

So at the risk of repeating myself just get a battery - The garage, i don't think they have a clue

I would get a battery like this and no more faffing around, its OEM rated for 90Ah but you can use a 95Ah battery just fine

Bosch S4 S40 28 95 Ah 830 A 306x173x225 mm

The specs of the battery fitted are 92ah 740A, what makes is "no where near the rated performance"?

 

[IAmATeaf]

If you do decide to replace the battery and want the Bosch then I've found Costco to be pretty cheap.

I did a search for that battery and couldn't find any info on it, except that there is a company in the US called PointS?

 

[ericmcn]

If you do decide to replace the battery and want the Bosch then I've found Costco to be pretty cheap.

I did a search for that battery and couldn't find any info on it

Because its a POS battery, i already have my point made. That Hyundai garage is just a waste of time also.

 

[IAmATeaf]

You can get the battery tested which would measure it's cranking capability can't you? Thought I read somewhere that this could be tested so might be worth doing? Other things which might be worth doing is testing the battery voltage after it's been off for say 24hrs although with the current clement weather that may indicate no real issues.

My gut feeling is if it was battery related than you'd get some unreliability where things regarded as not essential could potentially be disabled but the OP has stated that CA just doesn't work which must point to a fault/issue with the CA system.

 

[Meatball]

Because its a POS battery, i already have my point made. That Hyundai garage is just a waste of time also.

I’ve no doubt it’s a budget/rubbish battery but I’m dubious its the cause behind the keyless fault as everything else appears fine. I’ll get it tested and see what that says but for now I don’t want to buy a new battery if the current one, which has only been used for two 2 months, is ok.

I don’t think the Hyundai garage was a bad shout. They have the correct diagnostic equipment that can interrogate all the keyless components, not that it helped me much...

 

[ericmcn]

I’ve no doubt it’s a budget/rubbish battery but I’m dubious its the cause behind the keyless fault as everything else appears fine. I’ll get it tested and see what that says but for now I don’t want to buy a new battery it the current one, which has only been used for two 2 months, is ok.

I don’t think the Hyundai garage was a bad shout. They have the correct diagnostic equipment that can interrogate all the keyless components, not that it helped me much...

its your car at the end of the day. I would lose that no name battery as soon as I had the car if it was me but good luck. And I already said Diag equipment wont necessarily pick up a POS battery, which is what looks like happened here. Ask someone who has a snap on scanner

 

[IAmATeaf]

If you go here, you can get the service manual, which I think is for your car, on page 288 and after there is mention of an RF receiver which if the model is correct is behind the glove box, seems simple enough to remove the glove box and check that it's there and then check to see if it's actually plugged in. There is also a section on registering a new key but am not too sure

https://www.allcarmanuals.com/data/files/manuals/hyundai/Hyundai-ix35-tucson-2009-2015.pdf

 

[Meatball]

If you go here, you can get the service manual, which I think is for your car, on page 288 and after there is mention of an RF receiver which if the model is correct is behind the glove box, seems simple enough to remove the glove box and check that it's there and then check to see if it's actually plugged in. There is also a section on registering a new key but am not too sure

https://www.allcarmanuals.com/data/files/manuals/hyundai/Hyundai-ix35-tucson-2009-2015.pdf

That link doesn't seem to work.

 

[dale1uk]

The link half works, you just need to search for you car and then download the pdf file.

The description of the keyless entry in that file makes it sound like normal remote central locking though

"Description

Keyless Entry System

The burglar alarm system is integrated with the keyless entry system. The keyless entry system allows you to lock and unlock the
vehicle with the remote transmitter. When you push the LOCK button, all doors lock. When you push the UNLOCK button again,
all doors unlock.
DOOR LOCK / UNLOCK and panic operations are performed with remocon

Function
Keyless Entry Function
1. Keyless entry function is performed in a state that key in switch is eliminated from key cylinder
2. LOCK / UNLOCK and panic signals are received from the transmitter and DOOR LOCK / UNLOCK and panic signals are
output."

 

[Meatball]

Update: The garage aren’t being very helpful, they don’t seem to want to resolve the fault and instead keep mentioning giving me some money back - which I don’t want. He’s requested I speak to an auto electrician to see if they can find the fault which he’ll cover the cost of (apparently!)

As a test I put the key in the slot, started the engine and then took it straight out the slot again. The car didn’t even acknowledge I had removed the key and allowed me to drive all the way home without any warnings. Seems strange doesn’t it?

 

[Meatball]

Holy thread revival!

So the keyless entry and start still isn't working however I've made it my mission of lockdown 3.0 to get it working again. So a few minor updates:

• The garage that sold me the car has financially compensated me for the fault which I'm satisfied with
• I've had the car battery tested at Kwik Fit with a bosh tester after a few suggestions from you. It came back as 'good' but need a recharge? I found that odd as it's been used pretty much everyday and my commute is 40 minutes on the motorway one-way. The voltage was was 12.21v, measured 757 EN(A) and rating was 740 EN(A). Not sure what these mean?
• I've purchased a Hyundai specific VCI with software. It's on its way from China!

I've been testing the system a bit more and there are a few other odd behaviours which my help me solve the issue:

• Once I have started the car with a key fob in the holder I can remove it straight away and carry on driving with no warnings from the car. This does not seem right from a security point of view? I can even take the key out the car, walk in the house and the car will keep running without warning.
• If I leave my sunroof open, close all the doors and lock the car with the key fob button I do not get an audible warning the sunroof has been left open. I think I should get an audible warning? This maybe suggests some wiring above the headliner may be the issue as suggested by the dealership? Maybe it can't verify whether it's open/closed and has disabled the keyless for security?

 

[phil-k]

If your a member of the AA and have home start, call them
Edit: just read that you can actually start it so they probably won't be interested

 

[IAmATeaf]

I think the engine running is for safety, my car does the same, the key needs to be detected to start the car but then I can go into the car and the engine keeps running but on mine idrive will display a message related to the key.

Imagine being on the motorway, poor long along at 65 and the fob battery at that moment goes flat. To kill the engine would be unsafe.

 

[Meatball]

I think the engine running is for safety, my car does the same, the key needs to be detected to start the car but then I can go into the car and the engine keeps running but on mine idrive will display a message related to the key.

Imagine being on the motorway, poor long along at 65 and the fob battery at that moment goes flat. To kill the engine would be unsafe.

I don’t even get a warning the key is out though. It’s supposed to alert “KEY OUT” in the cluster if the key is removed from the car whilst running

 

[Howard]

Can you lock/unlock any doors using the keyless function or just the driver's door?

If any door, does the issue occur on all of them, the boot, etc?

 

[Meatball]

Can you lock/unlock any doors using the keyless function or just the driver's door?

If any door, does the issue occur on all of them, the boot, etc?

keyless lock/unlock doesn’t work on any of the doors (driver, passenger and boot.) Nor does the keyless start when you press the ‘Engine Start’ button, I get a ‘key not detected’ message on the instrument cluster and flashing immobiliser light.

If I leave the key in the fob holder, close all the doors and press the lock/unlock button on the driver/passenger outside handle I do get an audible warning from the car. This suggests to me that the door buttons are working.

 

[Howard]

But the remote buttons on each fob work perfectly?

At this point it sounds like something has gone amiss with whatever module controls the keyless entry/start, or maybe a sensor. The diagnostic tool you've ordered is going to give the most useful info I think!