zero point calibration ACR50 Previa power steering

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zero point calibration ACR50 Previa power steering

Postby BlakeNZ » Fri Dec 29, 2017 4:55 pm

Hi, can anyone talk me through doing a steering torque sensor zero point calibration without having the toyota scan tool? Vehicle is 2006 Previa(Nz new) with electric power steering (has had the power steering ECU replaced , but still shows the P/S fault light , and has VERY heavy steering). I have it booked in at Toyota, but they are busy, and closed for stats etc, so the vehicle is going to be off road for like 10 days if i can't fix it elsewhere. Any toyota mechanics here?
Last edited by BlakeNZ on Wed Jan 03, 2018 2:00 pm, edited 2 times in total.
JZZ30 soarer 1JZGTE 11.5sec@122mph(stock turbos,E85)
BlakeNZ
Toyspeed Member
 
Posts: 596
Joined: Thu Oct 03, 2002 1:53 pm
Location: Palmerston Nth

Re: zero point calibration

Postby BlakeNZ » Wed Jan 03, 2018 1:55 pm

Ok, so here is an update, so people know how to solve this issue in the future. It is a common fault on the ACR50, but there is VERY LITTLE info on the net about it, in relation to this model, so here goes.
The Previa/ estima/ tarago( australia) has a really good reputation for being reliable ( pretty much a Camry with 8 seats) however, the Electric power steering ECU is a known failure point, specifically, the main power feed relay inside. So technically, if you have the time, and know someone with the skills, you can remove and send away to fix. I will be exploring this option, to have a spare to offer to people on an exchange basis.
The steering ECU is located under the dash, just to the right of the steering column, and is secured by three 10mm nuts, and has a number of plugs. You have to remove some trim (but not the gauge cluster) to access it, a phillips screw driver will suffice.
The wrecker quoted me $450 for steering ECU, but given it is a common fault, this is too expensive for a part that is due to fail. A new one from Toyota was around $860 dollars from memory (can't recall if that was GST inclusive or not) Toyspeed discount brought that down to $813 including GST. I secured a new one from another source, with a further discount. The fault is so common, that they had the ECUs on their shelf, didn't even need to source them from the toyota wharehouse in Palmy.
After replacing the ECU, the P/S code was still showing, and the steering was still SUPER heavy. So it turns out you have to run the "steering torque sensor zero point calibration" (though the Diagnostic equipment at the local garage called it " a correction" rather than calibration.) So your local Toyota dealer can do this for you(make sure steering wheel is centred/ front wheels pointing straight ahead when you do this), however, as in my previous sentence, the local garage was able to do this for me.
So my 2006 NZ new Previa is up and running again. At 315,000km, this has been the first failure on it. Up until now, I have only spent money on maintenance items (oil/filters/some front brake hardware/trans fluid/coolant replace/tyres).
JZZ30 soarer 1JZGTE 11.5sec@122mph(stock turbos,E85)
BlakeNZ
Toyspeed Member
 
Posts: 596
Joined: Thu Oct 03, 2002 1:53 pm
Location: Palmerston Nth


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