Unique immobilizer system issue

[Dill Pickle]

Hi everybody. I need some help diagnosing what appears to be a very unique immobilizer system problem.

I have a 2003 TLC, with 92,000 miles. No indication of any problems, then this morning, it turns over normal, starts, runs for 2-3 seconds, then dies. It does this several times, and never starts.

The local Land Cruiser expert here in Boise pulled the following code: B2799, which indicates it is an engine immobilizer problem. He assures me it is NOT a problem with the key, and I believe him, as we have tested all three working keys, with the same results. He believes the immobilizer system and/or the computer are disabling the fuel system for some reason, but can't figure out why.

I am always amazed at the level of knowledge and expertise on this board, so please let me know if any of you have thoughts. This guy is a recognized LC expert in this area and knows what he is doing, but says he has never seen this before. He said we might have to send it to the local Toyota dealer, and I would like to avoid that if possible.

Thanks,
DP

 

[agaisin]

I know this is a TSB for the Tundra, but looks like what you're experiencing:
http://www.toyotapartsandservice.com/pub/pdf/TechCenterLibrary/TIS/T-SB-0078-09.pdf

Here's info on troubleshooting the problem from our FSM:
<start excerpt from service manual>
Either there's an "error in communication between ECM and transponder key ECU, and in communication line" OR "Communication ID is different in communcation with transponder key ECU".

The trouble areas to check are:
Wire Harness, Transponder Key ECU, ECM.

This DTC is output when the ECM detects errors in the communication between the Transponder Key ECU and the ECM, and in the communication lines.

This DTC is also output when the engine start is attempted with the COMMUNICATION ID between the Transponder key ECU and the ECM is different.

Before troubleshooting for this DTC, make sure that there is no DTC detected in the Transponder Key ECU. If there is Key code-related DTC (B279X) detected in the Transponder Key ECU, repair it first.
<end excerpt from service manual>

 

[Dill Pickle]

Thanks so much for the info and the quick reply. This is exactly what is happening. I shared this with my mechanic. He thinks the key transponder ECU is working so is going to try some other ideas first. I'll post an update if he finds anything particularly interesting.

This is the second time in my brief ownership of this rig that I have had trouble with electronic BS that I don't even want or need. The first time I had a gremlin in my anti-theft system, which was an easy and no-cost fix. Now, it's the engine immobiliser. I live in Boise freaking Idaho and don't need this stuff.

Sorry, venting.

 

[uHu]

This could also happen if you have two transponder keys close to the ign.switch, either two equal or two different.

This is what happened when I had the valet key on the same ring as the Master.

 

[Travis351]

Replace the EFI fuse in the fuse block under the hood even if it tests OK on your meter first. They do wear out. https://forum.ih8mud.com/100-series-cruisers/402506-1999-uzj100-intermittently-drops-dead.html
https://forum.ih8mud.com/100-series-cruisers/179908-help-im-irate-ignition-trouble.html

Take note of the flashing key on the dash and let us know what it is doing. Key in, Key out.