For completeness for this subject , I have updated the info as it will be useful for other readers if they wanted to clear the fault code and keep the engine management light off!
As my car is obviously over 12 years old and I don't think its justifiable to pay £170 per sensor replacement. I therefore where ever possible, I have attempted to simulate the heater element to "fool" the diagnostic as part of the ECU.
I have sucessfully simulated the heating element to remove the P0141 fault code:
P0141:
I used two high power resistors (50w, 8 ohms) and wired in series. The power dissipation is relatively small.
P1155:
I don't recommend to simulate this heater element as the heater element resistance is in the order of 1 to 2 ohms, i.e dissipates too much power and it will get too hot and dangerous. I therefore replaced it with a Denso OEM sensor from World Car Parts, Toyota car part no. 89467-42020, cost around £70. If you buy it from Toyota dealer you pay £170.
In order to remove the sensor, the manifold heat shield must be removed first. As the bolts and nuts (10mm) are all rusted, I have used penetration oil and applied it a few days in advance of any attempt to remove the bolt/nut (one application per day).
I then warmed the engine for about 5 minute from cold and then the bolt / nut was removed easily. (Where thick gloves to protect from the heat!)
From my observations, the grey connectors on the sensors are the pre-cat sensor and the heating resistance is very low, between 1 - 2 ohms. The other two black connectors on the other two sensors will measure around 16 ohms.
When the sensor or the heater simulator is fitted, I disconnected the battery for about 5 minutes to clear the fault codes.
I don't recommend people to do what I have done here and therefore I don't take any responsibility to any damage to their cars.
Enjoy......
Perfect.
Edited by Perfection on 05/04/2013 at 00:15
|
