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2008 Highlander Base
34,917 Posts
Discussion Starter #1 (Edited)
For Highlander Hybrid owners who want to do-it-yourself with repairs, listed below are a few links that may provide the help you need. For hard core DIYs, it might be a good idea to purchase a Haynes or Chilton manual that will answer most any repair question.

Also, because of the commonality with conventionally-powered Highlanders, owners with 2008+ hybrids should visit the 08+ Highlander forum's Modifications & Maintenance sticky, as well as the Common Problems & Solutions sticky for additional information. It's well worth the look for issues other than hybrid drivetrain, which is included in those stickies.

Hybrid Specific Information:

2011-2013 Hybrid CVT Fluid Change DIY

2014 Highlander Hybrid Specifications and Part Removal Steps

Audio and Navigation Schematics *Special thanks to Ewaybevinn for providing us with these schematics!

Hybrid Vehicle Maintenance from

Hybrid Car Maintenance from Be sure to check out the links on the right side of the page.

Offsite Link To Engine Temperature Hack To Improve Mileage Thanks to JSTCD for providing the link and details about the hack in this thread.

ScanGauge Codes (all known ones) for the 2006 hybrid but that might be applicable to other hybrid model years and other Toyota models too. Another special thank you to JSTCD for providing the document!

Transaxle Fluid Replacement: 1st Gen

Maintenance Information:

DIY: How to change the oil in your hybrid

Autozone is also a great place to start. This site has mechanical and electrical repair information for 2006 and earlier Highlanders. The wiring diagrams alone can be a great aid for do-it-yourself work.

Does your vehicle have an interference engine? Click here to check whether your Highlander (or other vehicles) have an interference engine. Just plug in your vehicle information and the "Comments" section in the results will tell you if it's an interference type, plus supply you with other pertinent information regarding replacing your timing belt/chain.

Free Car Fault Codes Got a fault code that you'd like to know what it means? This free web site offers a simple and easy way to get information about your fault code. You can also click on this link to view a list of OBD-II trouble codes.

OBD Port Location (picture provided by thaddeus)

Rear Hub Replacement - AWD 2008 HiHL

Timing Belt Or Chain, Which Does My Highlander Have?

Tire Size Calculator Great when seeking information for what happens when you change tire size.

Toyota Parts and Service This site provides scheduled maintenance requirements, and also provides service support links.

Toyota Parts East may not have guaranteed lowest prices, but what their parts site does have is an excellent listing of schematics, part numbers, and pricing when you search for parts. :thumbsup:

Toyota's Technical Information System contains all of the product support information necessary to maintain, diagnose, and repair your Highlander. TIS is offered on a subscription basis, so see the site for more information.

Vehicle Bolt Pattern and Offset Reference


Etrailer provides hitch installation, typical wiring diagrams, hitch rating info, and other information to help you with trailer hitches.

How Does The 4WD System In My Highlander Work? An excellent instructional video from Toyota. Thank you to R00K for the find!

Suggestions For Better Mileage thread

Tips, tricks, and suggestions by long-time owner Tydog07 located here for those who want more insight into their Highlanders.


AMSOIL Online Product Application Guide Need to know how much oil or fluid it will take when working on your Highlander? This excellent reference will give you that information and more, such as wiper blade part numbers or filter information. Check it out!

Battery Group Size Chart for when your battery goes belly up and you want to replace it.

Reference Source For Belt, Hose, And Hydraulic Work (see the "Popular Topics" sub-menu for quick links)

ToyoDIY Parts Reference provides parts information for any model of Toyota. It provides helpful, detailed information when ordering parts and is based on searching via you VIN number or frame number.

Vehicle Information:

AboutAutomobile is a great web site for finding out information on your vehicle, such as TSBs, safety recalls, consumer complaints, and much more! A site worth checking out. Special thanks goes to IBME for recommending this web site.

Online Toyota Maintenance Guide: Have you lost your owners manual or would just like to check on your vehicle's required maintenance information? This scheduled maintenance guide is a fast way to check it out.

Toyota Guide If you have questions about some of the features on your 2007 Highlander (sorry, they only cover 2007 and following years) then this site can help you with basic features like the key/fob, instruments, or controls. Toyota Guide has video demonstrations and interactive links that can answer some of the questions we owners may have.

Toyota Reference: A Collection of Vehicle History and Specifications is a great resource with helpful information about your Highlander or other Toyota. Thanks to scionlife for the site and link.

Send me or Moderator Ukrkoz a PM if you have a link/information that is generic for Highlander Hybrids that might be added to this thread. Any suggestion is welcome. Thanks, and check back occasionally for updates to this thread.


6,483 Posts
2012 Highlander Hybrid spark plug replacement

Additional issue to be resolved is hybrid has brake fluid canister and EGR valve assembly on the plenum left hand side, facing the engine. Where his review shows a large gap and thick wand of wires. So that gap, on hybrid engine, needs to be opened by dismounting and scooting those two parts to the side.

You MUST remove cowl and wiper motor mounting plate or, you are taking major chance with the infamous bolt on the L hand side behind the plenum. Just like described in the thread.
They did it for me yesterday at shop. Well, it's buddy, so it was quoted at $200. They took car in at 10, started on it at around 10 45. He called me back at 6 30, car was ready. He had several cars in works same day, so I am not sure how much exactly time it took to do the job.
When I cam there, he was shaking his head in disbelief.... Yep, they surely did pack them in there.
Btw, they did NOT drain coolant. That is mentioned in the official Alldata procedure. I think, EGR has cooling line attached to it. Maybe they simply managed to scoot it off to the side.
I drove car back home about 18 miles.
I used NGK Iridium plugs instead of Denso. Dealer wanted $833 before tax for the job. Plugs were $18 before tax each dealer. NGK at same warranty is $7 O'reiley.

6,483 Posts
Talked to the tech who did my plugs. Surprise. He did not remove air intake or throttle body. He said it took him about 2 hrs to do the job.
What he did was to remove cowl and wiper motor assy and metal plate it is on. Then he removed air filter box and hose that goes to throttle body.
Then he removed coolant hose to EGR on the left hand side and immediately plugged it with a rubber plug. Scooted hose out of his way and removed 2 large bolts holding EGR tube in place. Removed EGR. You can actually see one of the plugs right below the EGR tube. Then, he removed 2 bolts on the R hand side, behind and under throttle body, holding some sort of bracket, covering plugs, in place. He says that was it, he could then access all of plugs easily.

6,483 Posts
How to ad modern head unit to older HiHy without sacrificing display


I bought my 2006 in April. I for sure wanted the cassette player out from day one. In addition to that, the Navigation was belly up and I wasn't seeing anything that suggested that it could be repaired. Some updated tech was a must for me.

I was able to install an Android without sacrificing the main multi-purpose display at all.

It wasn't entirely easy. Apparently the energy monitor was designed to need the cassette player to function correctly. I don't know what the logic was there. But with some experimentation I figured out that the sole purpose of the 12 pin connector (with only two pins used) is to signal the multipurpose display that the cassette/stereo unit is installed. All the cassette/stereo unit does is apply a 70ohm resistance. I didn't happen to have a 70ohm resistor laying around, so I tried a random one from my scraps bin ...

There is also the matter of the steering wheel controls.

From left to right, that is SW2, SW1, SWG. There's no need to buy a fancy black box. You just need to connect those three lines to your new head unit as labeled. (I just happened to have a Toyota 20 pin connector that works for this in my junk bin.)

For the rest of the connections, the Metra 70-8113 adapter harness did the trick.

I'm planning to add a rear-view camera next ...

6,483 Posts
2012 Highlander Hybrid engine mounts replaCEMENT

Ok, I DIY-d all engine mounts.
Looking at the diagram attached, I did # 9, 6, 1, 3 and 7. 3 and 9 are torque mounts, they basiclaly reduce engine back fore play during acceleration and braking.
6, 1 and 7 are mounts, or insulators, proper.

1. torque mount # 9, aka dog bone. That is the biggest headache on this engine as it is covered by brake fluid canister. Canister sits atop of a bracket, held in place with 2 10mm nuts. When nuts are removed, unplug and disconnect fluid sensor harness and pull sensor out of the canister. Now, with slight resistance, it can be scooted away to open access to dog bone vertical, rear, bolt and to allow to get to bracket itslef 2 x 12mm nuts holding it in place to frame. One of those bolts, front one, is Ok to get to, but takes some contortion of hand to remove it off the stud and not to lose. Really scooting canister out of way and tilting it helps. The rearmost 12mm nut is pretty much covered by cowl. So either remove cowl or use flex head box wrench and same trick at the end - scoot and tilt canister and gently undo nut without loosing it.
Pull engine negative connectors out of the bracket side. I simply used needle nose plyers and yanked them - 2 - out. Take bracket out. Undo vertical dog bone bolt and take it out.
You will not be able to remove horizontal dog bone bolt as is. It hits brake actuator block and that's it. Hence, you need to remove entire bracket dog bone is connected to and then undo that bolt.
Bracket is #10 on diagram. It is connected to block with 4x15mm bolts. rear one is short, one in the "hump" is longest, 2 in the front are long same length. Rear bolt is also securing a short bracket with 2 x 10mm nuts on the opposite side. Undo those and remove bracket.
In front of the dog bone engine bracket there is thick grey wand of wires. held in place by round plastic clip. Undo clip, slide harness out and towards radiator.
Undo all bolts and slide dog bone forward then up and out, still connected to the bracket. In my case, rear, horizontal end of it was loose. I could move it by fingers.
Remove front bolt, install new dog bone on, reinstall everything.
At this point, you need to make 2 decisions: - are you replacing lower mounts? - do you want engine leaning forward or rearward?, as engine bracket is slotted where bolts go in, so you can actually tilt engine a bit either way and then lock it in place.
If you were only to replace the dog bone, then reverse removal and tighten bolts with engine pushed or pulled whichever way you want to. I have no advice there.
If you were to replace lower mounts, feed bolts in but do NOT tighten them as you will need to move engine up for lower mounts replacement. Basically, dog bone will be the only mount securing engine in place then.
2. Lower engine torque mount. #3. Remove passenger side wheel. It's right there, easy access. Remove dust caps for bracket 4 bolts in subframe. 14mm nuts. Remove nuts, remove nuts holding #5 to the engine block, remove entire assembly. Remove center bolt on #3 and install new one. As, after replacement, holes on engine block will be not coinciding with holes on #5, due to #3 being new, get jack under the engine and slightly jack it up, so that holes match. Reinstall all engine bolts and tighten. If you are removing other lower mounts, do not tighten #4 to the frame nuts. Just let studs sit in there. In my case, #3 was totally loose.
3. #6, 1 and 7. I had car up on lift, that helps a lot.
#1 has stud at the top going through engine block bracket into the mount. You will need a LONG extension to get to it from the top. It is rather hard to do anything from the bottom with it.
To remove it from the top, you have to remove air intake plastic piece connected to the radiator frame. Pop plastic clips on the driver side of plastic radiator cover. Access 2 10mm bolts holding intake in place. Remove intake. Radiator hose, partially covering top mount stud, can easily be moved to the side for access.
Remove plastic belly cover. All connections are 10mm heads. 2 front corner ones are screws.
Remove dust cap on one of the mount studs in subframe. Mount direction is marked with green dot forward.
Undo top mount stud. Undo 3 bottom 14mm nuts.
Remove both front wheels or, in case you had passenger side removed for #3, remove driver side one.
4. Side mounts. Driver side one, #7, has some sort of counterweight or balancer limiting access to upper 19mm nut. Remove its center 12mm bolt. Take it out. Remove top mount nut. From the subframe, remove 2 dust caps for studs. Remove all 17mm stud nuts.
Passenger side. Remove 19mm top nut, pop dust caps in the subframe, remove all lower 17mm nuts.
5. Take hydraulic jack and place piece of wood, 4x4 works best, on its plate. Move that plate so that it gets under solid transmission ridge, right next to the exhaust flange. 4x4 fits in there neatly.
6. Slowly start raising power train up. It will go up only so much. Eventually, throttle body air intake hits cowl and firewall and you can't move it any higher. Hence, watch the vehicle itself. If you start noticing that vehicle starts moving up - stop immediately! Or, it can come off lift or jackstands you have it on.
But, at this point, all mounts studs and bolts should be cleared enough to permit mounts removal. Driver and passenger side ones I pulled up and twisted out so that lower studs cleared frame, then pulled upper studs out of the brackets. Front mount went up, studs cleared frame, then I laid it horizontal and slid out towards the driver side, that way and down. There is enough opening to do so.
As where you have jack connected is not really center of the engine, it tilts towards the passenger side some. You may not have enough clearance for the passenger side mount to come out. Hence, reinstall driver side and front mounts. LOwer engine. Take wide board and slide jack under the oil pan. Jack engine up there, as then it lifts passenger side higher. Remove passenger side mount and reinstall new
7. Do not tighten front mount lower nuts until you managed to place upper mount stud in place. This requires some mount wiggling here and there, to match the hole. Do that, tighten top stud.
8. Lower engine completely.
9. Reinstall all nuts and tighten them. Place dust covers back in place.
10. If you left dog bone loose, now is time to finish its install.

You are done. About 2 hrs slow pace no rush job.

ALL OF MY MOUNTS were loose or very loose at 94 000 miles.


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