Central locking 12 year old Isuzu

[Thailand]

Remote key not worked for sometime so have been using ignition key which has worked fine. Last few days the system is playing up and key works sometimes. The feeling of the key turning in the lock of the drivers door is not as positive as it was.

Any checks I can be doing before I have to take the car in? Quite an expensive repair potentially I believe?

[Kwasaki]

When I had a Yaris it was the battery in the ignition key.

 

If not a electronic bad connection somewhere a shop that fixes electrical stuff on vehicles could find it not necessarily expensive. 

[transam]

Have you ever changed the key fob battery, mine usually fail at 4+ years...

[Thailand]

18 minutes ago, transam said:

Have you ever changed the key fob battery, mine usually fail at 4+ years...

Yes, it's not that. As I said the ignition key has been working fine until a couple of days ago. Loose wiring somewhere perhaps.

[transam]

Just now, Thailand said:

Yes, it's not that. As I said the ignition key has been working fine until a couple of days ago. Loose wiring somewhere perhaps.

The battery has nothing to do with ignition, it only operates the central locking, a chip inside the key fob does the ignition...

[Kwasaki]

53 minutes ago, Thailand said:

Yes, it's not that. As I said the ignition key has been working fine until a couple of days ago. Loose wiring somewhere perhaps.

Well car battery OK and new battery in key, off to shop you go. 

Could be the thingy that gets the signal from the key fob button that's the problem wherever that is. 

Edited July 10, 2022 by Kwasaki

[transam]

13 minutes ago, Kwasaki said:

Well car battery OK and new battery in key, off to shop you go. 

Could be the thingy that gets the signal from the key fob button that's the problem wherever that is. 

The fob has a transmitter which is battery operated to open the doors, only.

The fob also has a transponder chip inside that does not use the battery, the ignition switch has a "ring" around it which communicates with the fob chip to energize the car functions...

Has the OP ever changed the fob battery, 10 baht in Mr.DIY, can be done easily at home. First find out which CR 2000 battery it uses, one of 3. Google...

I would do that before anything else....

[Kwasaki]

1 minute ago, transam said:

The fob has a transmitter which is battery operated to open the doors, only.

The fob also has a transponder chip inside that does not use the battery, the ignition switch has a "ring" around it which communicates with the fob chip to energize the car functions...

Has the OP ever changed the fob battery, 10 baht in Mr.DIY, can be done easily at home. First find out which CR 2000 battery it uses, one of 3. Google...

I would do that before anything else....

His changed key fob battery for new so it must be the receiver signal thingy that triggers the door locks in the truck that may be faulty, bad or dirty connection, something has had a nibble etc etc. ????

[transam]

If the prob is just the ignition switch itself, does the main key turn but nothing happens, or is it the key will not turn the switch at all, but the spare does.

 

The spare also has a transponder in it to start the car. If it works no problem and the remote fob just will not turn the lock/switch, then the blade is naff/worn.

 

You can buy a new fob at a key cut place, cut the new blade from the spare key, the battery/transmitter goes in the new fob... 

 

[Thailand]

As mentioned, the key fob has not worked for some time.

I use the key, that has no fob. to start the car and up until now operated the central locking from the external lock on the driver's door.

Checked today, and the key, without the fob, will lock the central locking as before. However, it will only unlock the driver's door and not the others.

The problem has nothing to do with a key fob.

[HauptmannUK]

On this Isuzu the driver's lock is the Master Lock and the microswitches within it provide the lock/unlock signals to the other three lock motors (Slave Locks).  The fault is likely to be dirty/worn switch contacts within the driver's door lock.  A broken wire between the driver's door and A-post is another (less likely) possibility. A new door lock is about GBP200+ in UK. No idea of Thai price but won't be cheap.  Maybe try a secondhand part.

The central locking ECU responds to the signal from the remote and then fires off a pulse to the driver's door lock which then supplies lock/unlock signals to the other locks as described above.

The key transponder relates to the engine start immobiliser system and is nothing to do with the door locking system.

[Lancashirelad]

Get close to the door & listen if it's trying to lock when pressing the fob button. Remove the door card and look if there is any sign of movement in the locking mechanism, it may just need lubricating. On the other hand it could be a failed solenoid or relay. Any auto electrian should soon sort it out out.

[stratocaster]

Reading this reminds my of my wife's Volvo 960. Using the fob opens all doors and boot. Using the non fob key only opens the individual lock. I assume previously your key did open all doors. Have you tried resetting the fob ? Below is the reset for a 2010 Izuzu Adverturer so no guarantee it is the same so check your handbook.

Instructions
1.... Enter the vehicle, close all doors and insert the key into the ignition.
2 ...Turn the key to the "on" position, then press and hold the "lock" button on the remote transmitter for 1 second. Release the "lock" button, then turn the key to the "off" position. Repeat all the tasks in this step two additional times.
3 ….Turn the key to the "on" position, then press and hold the "lock" button on the remote transmitter for 1 second. The door locks will lock and unlock indicating the vehicle has entered remote programming mode. If the door locks do not cycle, repeat all steps to enter the programming mode.
4.... Press and hold the "lock" button on the transmitter for 1 second to program it. If programming is successful, the door locks of the vehicle will cycle. Repeat this procedure for each additional transmitter to be programmed, including older working transmitters. Three remote transmitters can be programmed and each must be programmed within 10 seconds of the other transmitters.
5 ...Turn the key to the "off" position to exit programming mode. Remove the key, exit the vehicle and close all doors. Test each transmitter by locking and unlocking the doors.