Anybody here know of an information resource for Hybrid Lexus?

[spelunkerd]

With extended warranties being in vogue, the non-dealer technician may not see many of the new vehicles until that warranty expires. My wife has a 2008 Lexus Hybrid, and it’s coming up to time to change the timing belt next summer. If I can get enough info to feel I can do it safely, without electrocuting myself, I plan to go ahead. My understanding is that the motor is very similar to older motors, so the main complexity is what to do with those orange (600V) wires. Generic manuals don’t yet include those models and I haven’t spent the dough to subscribe to the online dealer manuals (no OEM paper manual sold any more for new cars). Does anybody have a line on how to disable the big battery so I can work on the vehicle safely?

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[Physioex]

I have never worked on a hybrid vehicle. But I suppose the most important thing like you mentioned was to make sure you do not get electrocuted in the process. I would not recommend doing this without the proper information or guidance.

[EricTheCarGuy]

Your concerns are valid but if you don’t have the key in the ignition when you work you won’t have to worry about the battery as you work on the engine. Personally I prefer the factory service manual, I’ve been able to find them on ebay from time to time for much less than what you would pay for a new one, aside from that there really is no better information than the factory service information so it’s well worth the investment in my opinion.

[spelunkerd]

Thanks for your input, guys. I’ll plan to subscribe to the online manual, which is fairly reasonably priced considering what dealer manuals cost. I like the idea of an online manual, as long as I can remember what my password is. I guess you are pretty much assured it is up to date.

[jacobnbr1]

Yea it wont matter if they key is in or out of the vehicle nor on or off you can be killed if you mess with the orange wires! The 1st thing you need to do is disable the high energy system per the service instructions that I could explain if you could tell me the model of the vehicle.

[jacobnbr1]

Since the vehicle is a 2008 it has to be an ls600h. listen carefully to the instructions to disable and you will see why it doesn’t matter if the key is in or out.

To disable the high energy system there are two procedures.
1. a. Confirm status ready indicator in inst. cluster. If ready indicator is illuminated ignition is on. Push power button once to disable ignition. DO NOT PUSH POWER BUTTON AGAIN!
b. Disconnect 12 volt battery cables starting with the negative 1st and 2nd the pos (battery located in trunk driver side behind interior quarter panel. KEEP SMART KEY 16 FEET AWAY FROM VEHICLE AS IT IS AN IMMOBILIZER KEY AND ONLY THE PRESENCE OF THE KEY ALLOWS THE MODULES TO COME ALIVE.

Procedure 2. If the smart key cant be 16 feet away do the same as above but remove IG#2 relay from the fuse box on passenger side engine compartment bay.

[b]NOTE: HIGH VOLTAGE SYSTEM WILL REMAIN POWERED ON FOR UP TO 10 MINUTES AFTER THE HIGH ENERGY POWER SYSTEM IS OFF/DISABLED.

Courtesy of hybrid hazards and of course me.[/b]

[spelunkerd]

Thanks, Jacobnbr1!

I’m sorry, I should have said that it’s a 2008 Rx400h.

What I am hearing is that disabling the small battery should automatically disable the big battery, assuming those safety relays are functional. It sounds like I should be OK to work in the engine compartment, provided both posts on the small battery are removed, the key is not in the ignition or near the vehicle, and I’ve waited more than 10 minutes for capacitors to discharge. Of course common sense would steer a person clear of any orange wires. I thought there was a manual key somewhere under the back seat that manually disables the big battery near it’s source connections. Lexus should make this freely available to any people who need to know (firemen, emergency workers, etc)

[jacobnbr1]

Yes, please do not touch the orange wires at all, most hybrids have a master switch but Toyotas / Lexus (same thing) didn’t utilize this option at all which makes it harder for us emergency responders.

The rx400h is the same except the 12 volt battery is located in the engine bay passenger side and the relay to remove is igct#4 of the fuse box/relay center driver side engine bay area.

1. PRECAUTIONS FOR HIGH-VOLTAGE CIRCUIT INSPECTION AND SERVICE NOTE: The RX400h hybrid system contains a 288V high-voltage system with a strong alkali solution of potassium hydroxide. Be sure to follow the instructions to handle the system correctly. Failure to do so may result in serious injury or electrocution.

(a)Engineer must undergo special training to be able to perform high-voltage system inspection and servicing.(b)All high-voltage wire harness connectors are colored orange. The HV battery and other high-voltage components have “High Voltage” caution labels. Do not carelessly touch these wires and components.
(c)Before inspecting or servicing the high-voltage system, be sure to follow safety measures, such as wearing insulated gloves and removing the service plug to prevent electrocution. Carry the removed service plug in your pocket to prevent other technicians from reinstalling it while your are servicing the vehicle.NOTE: Do not put the vehicle into the READY-on state after removing the service plug grip as the ECU may be damaged.(d)After removing the service plug, wait 5 minutes before touching any of the high-voltage connectors and terminals.HINT: 5 minutes are required to discharge the high-voltage condenser inside the inverter.
And then this.

• Immobilize Vehicle Chock wheels and set the parking brake.

Move the shift lever to the P (Park) position.

• Disable Vehicle Performing either of the following two procedures will shut the vehicle off and disable the HV battery pack, SRS, and gasoline fuel pump.

Procedure #1
Turn the ignition key off.

1. Remove the key and place on dash.
2. If the key cannot be removed, disconnect the 12-Volt auxiliary battery in the engine compartment.

Procedure #2 (Alternate if ignition key is inaccessible).

1. Disconnect the 12-Volt auxiliary battery in the engine compartment.
2. Remove engine compartment covers.
3. Remove the fuse box cover.
4. Remove the IGCT No. 4 fuse (10A Red colored) in the engine compartment junction block. When in doubt, pull all four fuses in the fuse block.

WARNING:High voltage electricity can cause death or serious injury from severe burns or electric shock. To avoid death or serious injury wait 5 minutes after disabling the vehicle to discharge high voltage electricity, and do not touch, cut, or open any orange high voltage power cable or high voltage component.The SRS airbags can cause death or serious injury by sudden deployment. To avoid death or serious injury wait 90 seconds after disabling the vehicle to allow the SRS backup power to discharge.

If neither of the disabling procedures can be performed, proceed with caution as there is no assurance that the high voltage electrical system, SRS, or fuel pump are disabled.

[EricTheCarGuy]

Awesome info jacobnbr1, thanks for posting.

[spelunkerd]

Thanks Jacobnbr1, I’m glad I checked back in to look for more replies. It sounds like you are a paramedic or fireman. I printed out your advice to keep in the glove box.

In some of the Lexus literature (on their website) they talk about a service plug, that you can pull out and so manually disable all the ornage wires. I looked for such a plug where a diagram from Lexus showed it, under the left rear seat, and it doens’t seem to be there. Maybe as you say, it is not available for this model. I guess pulling fuses is just as effective.

[jacobnbr1]

Glad to help out. S:)

[Author]

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