remotes not working still

My remotes (2) do not work for a while now. I have to open and close the doors with the key. I changed out the passenger door ajar switch which now triggers the door ajar dash light and center overhead light. After I performed the routine described in the SM with door open/closing, key in and out etc to reprogram the remote but no result.
The specialist who provided me with a duplicate remote, tried to get them working before I changed the switch. He told me when hooking up his device to the connector under the dash that he could not get a signal from the ECU.
What can I do to get this working?

 

When you turn you key to run, but engine off, does the engine light come on?

 

Yes it does.

 

I am thinking this has to do with the immobilizer... the little red truck blinking light near the climate (heater/ac) controls.
Is it blinking when put the key in the ignition and try to start the truck?

 

How would changing out a switch 1) affect the remotes and 2) result in the engine light illuminating?

 

Did your remotes fail simultaneously, or one failed first, then the other stopped working a bit later?

You might be able to use an obd device to program a new set of remotes, if it’s just the remotes that went bad, and not something internal to the truck. Based on remotes going bad separately at different times in a similar aged car, i think this is the most likely case. I don’t know what the max number programmed to the truck is for the 2nd gen taco. For 3rd gen and other toyota vehicles i have seen 5 masters + 3 valets posted in comments, per techstream, but have not seen first hand yet.


You can buy the obd device to add remotes or chip keys on ebay. The Tom’s key video on youtube was the clearest instructions to actually use it, but Tom’s key charges a few times more than it will cost to get the items from an independent seller on ebay, and you also have to mail their obd device back. The obd device https://www.ebay.com/itm/233163863246? i got on ebay worked exactly the same way, with no need to mail it back. It was green plastic and somewhat poorly labelled vs the red/orange obd device in the tom’s video. I also used an obd extension cord with a switch like this

OBD2 Cables, Low Profile 60cm OBDII 16 Pin Male to Female Diagnostic Extension Cable Cord with Switch

https://www.amazon.com/gp/aw/d/B07QLRMVDH? Plugging/unplugging directly could be awkward

 

going through something similar
I need to figure out what receives the signal. It should be an antenna unit somewhere. They typically are a green circuit board with plastic backing that can crack over time. Not to mention Toyota known for solder connections cracking.

weakening signal

remote and key are two different things.

Fob means programmed to unlock and whatnot.

key means immobilizer chip programmed that when ignition is turned on, a coil is able to successfully read to allow engine running. Typically somewhere in the column near or attached to the ignition lock cylinder.

usually a control module responsible for locking is located elsewhere, with a wire that connects it to an antenna (usually by a window, such as under headliner) to receive fob signal

that’s assuming fob is programmed correctly, is the right type to be compatible (such as MhZ required)

and known good battery in the fob
Meaning high quality battery dealers use, not grocery store or Home Depot

if there was an immo issue, would be an immo light flashing on dash and engine either not starting or turning back off after a few seconds.

researching now
Supposedly receiver is hidden behind glovebox
and looks expensive new

not saying this is the cause
But be sure main battery is good
Vehicle electronics act weird if it’s not.

 

I believe the remote and the g or h chip next to the key are completely independent of each other’s functions or failure to function though. The g or h chip only stops the blinking red lock light and the immobilizer/allows starting sequence. The chip is a tiny thing inside black plastic that sits inside the key’s handle closest to the part of the key that goes inside the lock. The remote needs a battery to send the signal tell the vehicle to lock/unlock/panic-horn and . Sometimes the terms used like transponder are confusing as to which device is meant.

 

I may have missed this but did you verify the batteries in your remotes still have the 3V needed? I like to check them with a multimeter to be sure. On rare occasions, I've gotten a bad, new battery.
I know, Captain Obvious stuff here but I didn't see it mentioned...

 

Yes fresh batteries installed. And again when the specialist who supplied the spare remote came to check he too checked the batteries.

No it is not blinking.

They failed simultaneously. The specialist who supplied the spare remote has such a device and he told me when hooking up his device to the connector under the dash that he could not get a signal from the ECU.

 

The Remote Keyless Entry (RKE) system is completely separate from the engine immobilizer system, the RKE system consists of the Door Control Receiver and Body ECU neither of which are capable of talking to a scan tool.

The Door Control Receiver (behind glovebox) handles the remote functions & sends the signals to the Body ECU (left of steering column behind knee bolster) which controls the door locks.

If there is a key in the ignition, the Body ECU "thinks" there is a key in the ignition,ignition is on, or one or more doors are open the remote functions will not work, easiest way to check for this is to see if the key in chime sounds with the door open and key out and also make sure the door ajar light goes out when all the doors are closed.

If you post your year model I can post the relevant wiring diagram.

 

Just for reference here is the complete procedure for various programming modes of the FOBs.

Here are the complete process for programming the remote FOBS. You may want to clear everything and reprogram the truck to receive the FOBs you have. Note: The info in RED for other models.

Try this. There are 4 modes. You should use Rewrite Mode to start over and only program the remotes you want to use.

There are four different programming commands when setting up or verifying your remote transmitter, they are:

1. Add mode, used to add a remote to your car that is not currently registered.
2. Rewrite mode, used to erase all previously registered remotes and allow you to begin again the programming process.
3. Confirmation mode, used to verify the number of remotes that are already programmed in your car.
4. Prohibit mode, to prohibit all remotes from operating the door locks.

https://www.carandtruckremotes.com/...eplacement-keyless-entry-control-remotes.html

Procedure To Program Toyota Wireless Remote Transmitters:

Begin with: The driver's door open and unlocked. Key out of the ignition.

1. Insert and remove the key from the ignition switch 2 times within 5 seconds.

NOTE: Steps 2 and 3 should be performed within 40 seconds.

2. Close and open driver's door TWICE.

3. Insert the key into the ignition and remove it.

NOTE: Steps 4 - 6 should be performed within 40 seconds.

4. Close and open the driver's door twice.

5. Insert the key into the ignition.

6. Close the door.

NOTE: Steps 5 and 6 should be reversed for the following models ONLY (close door first, then insert key into ignition):

2000 - 2005 Celica

2001 - 2003 Prius

2001 - 2005 ECHO

2001 - 2005 RAV4

2003 - 2004 Avalon

7. Turn the ignition switch from "Lock" to "On" and back to "Lock" at about 1 second intervals to select the desired mode:

1 time for ADD mode.

2 times for REWRITE mode.

3 times for CONFIRMATION mode.

5 times for PROHIBITION mode.

8. Remove the key from the ignition.

9. To confirm your mode selection, the power locks will now cycle "lock" to "unlock" a number of times corresponding to your key cycles in step 7.

NOTE: If Confirmation or Prohibition modes have been selected, opening the door will complete the procedure.

10. For Add or Rewrite modes do the following within 40 seconds of Door

Procedure Lock confirmation:

A. Press both car transmitter Lock and Unlock buttons simultaneously between 1 and 1.5 seconds and release.

B. Within 3 seconds of step A, press the transmitter Lock button for more than 1 second and release.

If the keyless entry remote transmitter has been successfully programmed, the power locks will cycle "lock" to "unlock" once at this time.

If there are problems with the remote transmitter or the procedure up to this point, the locks will cycle twice. If this occurs, verify that you have received the correct transmitter, and then repeat the above procedure.

C. If multiple remotes are to be reprogrammed, repeat steps A and B.

11. Open the driver's door to conclude programming mode.

 

The ECU-b fuse is used by the wireless transponder. OP says no engine light and no ECU communication.

We have to start some where.
I usually like to start with the shared commons.

 

Thanks.
Door ajar light works fine on both doors.
The key chime in does NOT work with the door open and key out. It also does not work with the key in and door open.
Once in a blue moon it works with the key in and door open. That happened maybe 5 times the last 3 years I have the car.

 

2007 ext cab rwd 2.7 4cyl

 

I'm not really sure what else to test, have you verified your remotes work?
Many parts stores have a tester sitting on the counter that you can use to see if they are outputting a signal.
Also check behind the glovebox that the Door Control Receiver is plugged in.

I'm assuming you have factory keyless entry?

 

Yes factory keyless with one factory remote and one clone.
The supplier of that probably checked if they both work before attaching his scan tool to the car.
I will double check it at a parts store again.

I will check that the DCR is plugged in.

That my key in chime does not work at all is not a factor in this issue?

 

I wouldn't think so as long as it's not beeping with the key out, wouldn't hurt to test it though.

With the door open and key out hit the lock button on the door, if it locks and stays locked it's good. If it locks and immediately unlocks then it thinks there's a key in the ignition.

 

Thanks. It stays locked.

 

Nothing is unplugged.