Foreign Service

Motor, Mar 2005 by Marinucci, Dan

The 'key' to cost-effective repair of immobilizer-equipped Toyota models is determining what system is in the vehicle, as well as its quirks and capabilities.

Last month, I explained the fundamental operation of the immobilizer, a security system Toyota introduced in 1998. Don't miss that column because it provided practical troubleshooting tips as well as the foundation for this month's material.

Replacing lost keys or a failed ECM on an immobilizer-equipped Toyota may be more complicated than you thought. A little information here goes a long way toward preventing some very embarrassing moments for yon and vour shop. Prepare yourself by learning the following immobilizer service scenarios.

The first involves the latest version of the security system, which has a stand-alone immobilizer computer hidden somewhere under the dashboard. If the customer loses all his master keys, he must purchase new keys and a new iminobilixer computer. This new computer is already in a state called open-registration mode. So, install it and slide a new master key into the ignition switch. Turn the ignition switch on (engine off) and leave it on for about 30 minutes. This automatically registers or mates the new master key to the new computer. Then follow the procedure for adding master keys, which I'll describe later on.

Because the immobilizer function on this system is totally separate from the traditional ECM, the security system doesn't affect ECM replacement.

The second scenario concerns a Toyota vehicle on which the immobilizer function is built into the traditional ECM. However, this computer is resettable or rebootable. If the customer loses the master keys to the vehicle, he doesn't have to buy a new ECM. Instead, a dealership technician can reset or reboot the immobilizer portion of the ECM and create new master keys at the same time. The tech does this by accessing the security system with an OE scan tool and Toyota's in-house, PC-bused technical dutu system called TIS. Believe me, this is a highly specialized task best left to someone trained and equipped for it.

Suppose an ECM failure occurs on an immobilizer-equipped Toyota with this resettable type of computer. If you install a new Toyota replacement ECM, the jobs a snap because this computer's already in the open-registration mode descrilied earlier. Turn the ignition switch on (engine off) and wait 20 to 30 minutes. Whatever key is in the ignition switch during this step becomes the new master key. Then you can register additional master keys as needed. Check with your ECM supplier, because a remanufactured computer in open-registration mode may not be available. Remainufactnriug specialists told me that availability should improve as the vehicle manufacturers release more data for reprogrammiiig and/or updating ECMs.

The third security system scenario you need to know also involves a traditional ECM with the immobiliser capability built into it. But dus one cannot be reset or rebooted. If a Toyota has this type of immobilizeer, a customer who loses the master keys has no choice but to replace the ECM. What's more, you can't throw any old salvage-yard ECM into this kind of vehicle, either.

Before I delve any deeper into these three scenarios, I'll list the immobilizer-equipped vehicles that may have a nonreset type ECM. Keep the list handy and check it anytime a Toyota owner has lost his master keys. Also refer to it if you're thinking of replacing a tidied ECM with a salvage-yard part.

* 1998-2000 Land Cnusers'

* 1998-2001 Cainrys

* 1998-2004 Avalons

* 1999-2000 4Runners

* 1999-2003 Siennas and Solaras

* 2000 RAY4s

* 2001-03 Highlanders

If the vehicle in your bay is among these, give the local Toyota parts man its VIN, model type and options. He'll cross-reference this information with that in TSB No. 03-09 and tell you if the vehicle has a nonreset type ECM. Suppose he verifies that it has a nonreset ECLM and the master keys were lost. In that case, Toyota will replace the ECM free of charge. The customer still has to pav for new master keys and for any labor charges, such as computer H&H. Note that according to the senice bulletin, this courtesy ECM replacement doesn't apply to a vehicle purchased at auction without master keys.

Let's go to the next scenario. You diagnose an ECM failure of some kind on one of these vehicles with the nonreset style computer. The customer is bugging you about cost and suggests you save money by sourcing a salvageyard ECM. I'm not here to debate the wisdom of installing used parts. But I am here to urge you not to try this unless the salvage man sends you the correct ECM as well as a master key from the vehicle he disassembled. Without a matching master key, a nonreset EC]M from a salvage yard is worthless! (I know of at least one '98 Avalon auction car with a junkyard ECM that's (jut of commission for want of a master key.)

Suppose the salvage man sends you the correct ECM and a matching master key (rom the "source" vehicle. Following this simple procedure will get the vehicle on the road again. For now, let's call the matching master key from the junkyard vehicle the jnnkyanl key. Let's call the master key in the customer's ignition switch the customer's key. First, have the local lock shop cut a duplicate of the customers key. The sole purpose of this duplicate key is to operate the ignition switch. Put the customer's key aside and slide the duplicate key into the ignition switch.