Wrong model year AHC pump, please tell me there’s an adapter for this (2 Viewers)
- Thread starter kunu
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Use the old sensor?
- Thread starter
- #3
Are you saying to take apart the 2 pumps and swap them?
Yeah, is it that large sensor in the pic? Probably identical except the plug. But take the old one out first to be sure nothing unexpected happens so that you can still return the unmolested new one if there's a problem.
Maybe also wait for someone else to chime in in case I'm missing something but If it was mine that's what I'd try.
- Thread starter
- #6
Here’s some better images of what they look like. I’ll hold out for some more info before I get crazy.
I also got this off IMPEX, so no returns. It’ll just go to a mudder on discount probably if there’s no fix
Look the same to me, both 3 terminals just a different plug .
IndroCruise
SILVER Star
Assuming the discussion is about a 1999 LX470 (?)
There are a few "known unknowns" here and maybe some "unknown unknowns" to consider ....
At least two different Pressure Sensors were used on the AHC/TEMS hydraulic circuits and control circuits on LC100/LX470 vehicles when manufactured in different Model Years:
Part Number 89192-60100 from 01.1998 to 08.2000 (according to Partsouq and other sources for Parts) with the three-pin flat connector, and,
Part Number 89192-60020 after 08.2000 and ever onwards (?) with the three-pin triangular connector.
There is only one Pressure Sensor in the hydraulic circuit and control circuit for AHC/TEMS.
This Pressure Sensor provides vital inputs to the Suspension Electronic Control Unit (ECU) to enable nearly all of the AHC and TEMS functions to work properly.
So the Pressure Sensor has to be the correct item and must be healthy and functioning correctly to deliver the required voltage signals to the ECU for correct AHC/TEMS operation.
Unknown for sure but most likely this AHC/TEMS Pressure Sensor is a piezoelectric device which converts pressure to a voltage signal. (Other alternatives are "piezoresistive" or "capacitive" devices -- Google if interested, otherwise not worth getting lost in this detail).
The good news is that the AHC/TEMS Pressure Sensiors are longlasting and reliable -- there are very few IH8MUD reports about failures of Pressure Sensors. That said, unless DTC C1718 appeared and the appropriate tests were done (see attachments), it would be hard to recognise failure or deterioration.
One of the "unknown unknowns" is whether or not the different Pressure Sensors are interchangeable and compatible on different Model Years??
The milled block (Part Number 48905-60010) carrying the AHC Pump on one side and the Motor on the other side, also carries the fluid Pressure Sensor, the fluid Temperature Sensor and the Return Valve (internally). This Part Number appears to be common across Model Years for all LC100/LX470 vehicles with AHC/TEMS, so either Pressure Sensor could be expected to fit in the large threaded hole for the purpose.
Further good news is that replacement of the milled block Part Number 48905-60010 means that the Return Valve has been replaced. It is included inside Part Number 48905-60010. The Return Valve can be problematic -- prone to blockages in older vehicles, especially if AHC Fluid rarely has been changed.
However, the attached different test procedures and measurements suggest that the different Pressure Sensors may have different electrical characteristics.
In addition, the Part Numbers of the Suspension ECU are different for different Model Years.
Suspension ECU Part Number is 89290-60021 for LX470 in 1999,
Suspension ECU Part Number is 89290-60041 for LX470 in later years.
So compatibility of different Pressure Sensors with different Suspension ECU's is unknown -- unless someone somewhere has proved it one way or the other???
RECOMMENDATIONS:
OPTION #1:
Acquire a 'pigtail' per link below and make up an adapter to connect the existiing 1999 harness to the new Pressure Sensor in the new Pump Assembly.
90980-11451 Genuine Toyota Housing, Connector F - https://www.toyotapartsdeal.com/oem/toyota~housing~connector~f~90980-11451.html .
It may work or it may not. If it works, good.
If not, nothing much lost except time and about USD10 -- move to OPTION #2:
OPTION #2:
Remove the Pressure Sensor from the old Pump Assembly and test per relevant FSM attachment.
Remove the Pressure Sensor from the new Pump Assembly and test per relevant FSM attachment.
(Just good housekeeping to test parts before installing or reinstalling).
It it tests OK, instal the old 1999 Pressure Sensor in the new Pump Assembly and install in the vehicle.
This should work. If so, good.
If not -- move to OPTION #3,
OPTION #3:
Buy and install the correct Pressure Sensor Part Number 89192-60100 for LX470 built in 1999.
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