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Hybrid TechnologyUnique topics related to the 2004 -2009 RX400H model hybrid drivetrain and other features/options found only on the RX400H. Please use the main forum for discussion about shared components with other second generation RX models.
Well, this is my first post here, although I have certainly benefitted from this site already while poking around over the last year.
We managed to purchase a pristine, very well maintained 2006 with less than 100K early last year and had no real issues with it whatsoever.
I did replace the 12V battery after getting the typical codes. This time is different however...
We experienced the CHECK HYBRID SYSTEM - CHECK VSC SYSTEM lights and indicators a few weeks back, which did not produce an error code that I could retrieve with my OBDII reader.
This occurred on a rather hot day >30C and at highway speeds of 120k\h.
I cleared the codes, to see if it would hard fault -- it did not.
Last Saturday, same thing happened in the same conditions, which was a perfect opportunity to pull into the dealer (for the first time) and get the proper diags, etc.
They have come back with a long list of really high priced parts and replacement parts -- one of which will be the radiator ... covered in another post.
Of greatest concern to them is the P2603 error code which they have determined to be a suspect HV oil pump P\N 35300-48011 at a quoted price of $1413.70 CDN.
There seems to be very limited information on this, although there is some strong indication that this could just be a corroded connection (which they checked for) or
a failing relay. This still has not hard-faulted since the code was cleared last week. For some reason, I feel I may want to replace a $25 relay as a first choice.
Well, as I work through this transmission oil cooler pump issue, I figure I should document it to let you all know that I do value the forum enough to provide information for others to use.
I found the relay marked as "oil cooler" and have taken a few photos -- it is nothing special.
On this note I should mention that it has occurred to me that the transmission oil cooler pump may NEVER have been needed prior to last summer on our trip.
Considering the previous owner did not have a hitch and I was told they also traded in an Escalade that was used for towing boat and going north to the cottage when they traded in this RX400h, it is plausible that either the relay or the pump may be totally corroded...and perhaps, present some risk by coming on at some point. I added one, based on this forum recommendations and instructions - thanks for that.
Here are the pics of the relay - TOYOTA P\N 90987-02027, DENSO P\N 156700-2870.
I have ordered the relay for $30 CDN including shipping.
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So it is corroded however the socket may be damaged. I would use a liberal amount of contact cleaner. It is possible the relay is ok, just need to clean contacts.
So it is corroded however the socket may be damaged. I would use a liberal amount of contact cleaner. It is possible the relay is ok, just need to clean contacts.
Thanks for the tip!
The socket does look somewhat corroded, for sure. Although I suspect it may be the relay contacts internally that are corroded, so I plan to pop it open after I get the new one into it tomorrow.
Hi!
Any success with that issue? Does the relay replacement solve the problem? Or is it anyway oil pump failure? I have same P2603 error on my 450h. Relay seems to be fine.
Hi!
Any success with that issue? Does the relay replacement solve the problem? Or is it anyway oil pump failure? I have same P2603 error on my 450h. Relay seems to be fine.
Did do a test of the pins on the relay -- was expecting continuity between the two pins going to the motor, although I do not have a schematic and it did NOT have continuity between them.
Next step is to disconnect at the pump and pin check from relay down to connector to make sure wires are good.
After that -- Pull the pump and disassemble.
Can anybody help me locate the correct tools for these screws?? There are a couple Tri-Wing screws holding on the heat-sink, but it is the 5 pointed star bolts that I am most interested to get so that I can dismount the motor from the actual pump. Somewhere I came across the term "pentalobe" which brings up all kinds of screwdrivers for Apple products, Macbook, iphones, etc. But not anything this size...see below....
Where can I find a screwdriver or socket driver for the 5 point bolts??
Those are Torx bolts. Dread them. they are everywhere now and come in two flavors - regular one and so called security one, that requires T-through Torx tool, as it has pin in the center of the star shaped recess. I just had to replace multifunction switch on my RAM and had to go and buy 2 Torx screwdrivers just for that purpose, to the tune of $15.
Thank you for being diligent poster. This helps everyone a lot.
OP, as advanced as you got into all this, you must have Techstream s/w and OBD2 to laptop cable. Many things on hybrids CAN NOT be done without Techstream, aka TSI. Say, brake bleeding. Or, inverter pump bleeding. Happens to be so inverter fluid also is cooling fluid for PSD - power split device, which is transmission on HSD - hybrid synergy drive. Inverter pump solenoids have to be moved by TSI during bleeding procedure.
Those are Torx bolts. Dread them. they are everywhere now and come in two flavors - regular one and so called security one, that requires T-through Torx tool, as it has pin in the center of the star shaped recess. I just had to replace multifunction switch on my RAM and had to go and buy 2 Torx screwdrivers just for that purpose, to the tune of $15.
Thank you for being diligent poster. This helps everyone a lot.
So the relay swap did not fix the issue?
Appreciate the feedback everyone -- no, those are not Torx -- Torx is 6 point star -- these are 5 point, which makes it more challenging.
I do have multiple sets of Torx, including the the security set (my daily driver is Volvo -- mostly all Torx)
No, there is really no way to tell if replacing the relay solved anything, only that I know the old one bench tested fine and the new one behaves the same way on the bench.
Kicker of this whole problem is that the pump only goes to turn on when car is loaded and on 28C or hotter days....thus, no error or lights since the incident in July.
QUESTION -- am I foolish to consider removing pump altogether?? My understanding is that it is an option to begin with...just a thought!
Yes, 5 point star is it!!
Now oddly enough some tool descriptions also call this Torx, which seems odd to me.
YES I want to remove and disassemble the electric motor from the pump and check both components separately -- this should just be a DC motor on a constant displacement pump.
Certainly, it is not worth the $1400 CDN that the dealer quoted to me!
Yes, 5 point star is it!!
Now oddly enough some tool descriptions also call this Torx, which seems odd to me.
YES I want to remove and disassemble the electric motor from the pump and check both components separately -- this should just be a DC motor on a constant displacement pump.
Certainly, it is not worth the $1400 CDN that the dealer quoted to me!
This trochoid type oil pump is driven by the motor, which is operated using duty control, performed by the motor driver, based on instructions from the power management control ECU.
This is the RX450h diagram, connectors and pins could not match: Oil Pump
Just found this thread. Have a 2010 450h with same error code. Toyota garage says it's the pump mentioned here. Question is can i trust the $500 parts from ebay and can a parts-changer like myself do it thus saving abot $1800? Appreciation to those in the know.
07-21-17 | 08:40 PM
Rx400H Transmission Oil Pump - Error P2603
