Intermittent immobilizer malfunction B2799

[utmba95]

Hi, about once a year over the last 3 years, my immobilizer acts up and my 4runner won't start for about 15 minutes. I'm not sure if it's anything I'm doing or just time lapsing that resolves it. I verified that the flashing red key light goes away when I put in the key even though it's not starting. Anybody have any insight?

 

[SocalSam]

I have not worked on a Toyota immobilizer system but I know a little about Ford. There is an energizer on the ignition lock cylinder that activates the key chip which sends signal to the immobilizer module. Immobilizer module authorizes ECM and we get engine start. In a Ford, this key energizer is a ring that fits around the lock cylinder. Suggest you check wiring to the Toyota energizer and or replace the energizer part. Sorry, I can't be more specific.

 

[utmba95]

I have not worked on a Toyota immobilizer system but I know a little about Ford. There is an energizer on the ignition lock cylinder that activates the key chip which sends signal to the immobilizer module. Immobilizer module authorizes ECM and we get engine start. In a Ford, this key energizer is a ring that fits around the lock cylinder. Suggest you check wiring to the Toyota energizer and or replace the energizer part. Sorry, I can't be more specific.

Since the red immobilizer light goes out when the key goes in, I assume the energizer is working.

 

[SocalSam]

Since the red immobilizer light goes out when the key goes in, I assume the energizer is working.

Yes, that is good assumption. Maybe the key chip is shakey. Try an ebay chipped key. I bought a couple of years ago for cheap and they are working great.

 

[ArthurKotb]

Since the red light goes out when you insert the key I would suspect the immobilizer ECU. There's supposed to be an antenna with the ECU so maybe there's something going on there. Trying another key is always a good idea. Does it behave the same way with a different key?

I think the device inside the key is like those RFIDs in expensive stuff. When you go past the devices at the door they send a signal to the RFID and that responds with an alarm. If the code isn't right it won't start, or, I guess, if the antenna or ECU can't read it, same thing; no start.