Avensis Immobiliser Fault B2799

[spearos]

Hi All

Just returned from Marsh Toyota plymouth. They have run diagnostics on my 2004 Avensis D-4D T Spirit 57000 miles. Engine 1CD-U097821.

Symptoms:

On two separate occasions engine turned over but did not start (1 month in between). AA called, full Battery load test done and Battery is fine. Did start when he put boost cables on Battery ????

Diagnosis report:

tested for hard start. Tester fault code stored b2799 relates to engine immobilizer fault, further diagnostics required 45 quid, and thank you very much.

Was then told that to further diagnose requires dash removal, 6 hours labour to get to the immobilizer circuit. approx. 550 inclusive of vat. Then spoke to a recommended auto electrician who said that to get into the immobilizer circuit is a dealer only job.

Please, please any comments?

The only reason I went with Toyota was reliability and I have been failed within 6 months of ownership. Any comments please.....................

[Beagh1958]

Code shows up as wiring harness fault or fault between engine ECM unit behind glove box, and key ECU transponder. Have never had this fault before, just using wiring diagrams that i have to hand. Cannot locate Key ECU transpomder, which i must admit i have never heard of before, may also be known as one of the following or by a different name by Toyota.

1/. Immobilizer control module, located by ignition

2/. Immobilizer read coil, near ignition switch. Does as it says reads signal from key as with all other vehicles.

Sorry but i think your looking at a nightmare job, maybe reason why your auto electrician seems a little shy of it. I don't think any Toyota mechanics would be running to the front of the queue for this job. If it has only done this twice, it could be that car is not reading key code, maybe bad connection if lucky. From chart it looks like a dash strip down. Unless key playing up ?????

Good luck. Regards, Beagh.

[PhilGee]

Try your other keys when the fault happens. If it starts ok with other key then probably just a key fault. Also, some Avensis dont have a seperate key code/immobiliser ecu, its built into the main engine ecu.

[Sooty]

Try your other keys when the fault happens. If it starts ok with other key then probably just a key fault. Also, some Avensis dont have a seperate key code/immobiliser ecu, its built into the main engine ecu.

Hi, I have a 2001 avensis GLS 2 lire vvti and sometimes get the same problem of not starting.

All I do is switch off and lock/ unlock the doors twice using the buttons on the key.

It then starts with no problem.

I think what is happening is the immobiliser and key change codes at different intervals and by using the buttons you are re-syncing the codes.

Some manufacturers put this into the design to try and stop thieves running around with spare transponders to steal the cars.

Hope this helps.

Sooty

[spearos]

Hi all

UPDATE

car failed to start again today on garage forecourt. bugger

Had spare key, so tried every which way possible with no result.

After AA guy turned up, he boosted Battery with no affect, plugged his Vixen laptop in which told him there was no fault stored on the EOBP but the air temperature sensor reading was +40 degrees C. (car had been stood for an hour and a half on a cool day before he plugged the laptop in) He said this was an incorrect reading.

He then disconnected the Air mass meter, turned it over and it started straight away. He then re-attached the air mass meter plug. On stopping the engine the car re-started without any problem.

His diagnosis was a suspect air temperature sensor or associated wiring problem.

Would you guys concur taking into consideration the previous post i made about the original problem.

Many Thanks

Toby