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Rx8 electric power steering problem


Benginetuner

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Hi all. I've just put a thunder in my rx8 running a 1jz vvti. I've had the car running on stock jz management with an emanage blue for a year now without any issues. 

 

I've swapped to the thunder for obvious reasons. The car side of things is currently still as it always has been. 

Since installing the thunder my electric power steering fails and throws up a B2278 code. Torque sensor malfunction. I can see in the live data its operating within range. Sometimes it starts up fault free, most times it throws this code. 

 

Anyone else encounter this? 

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Hi Adam. Thanks for the reply. 

 

Yes it currently has the stock rx8 ecu in place controlling the dash etc. I've got the thunder wires run to where the stock ecu is with a view for the thunder to control the dash. 

I've got the can file example you uploaded in another thread loaded on the laptop ready to put it. 

Will it need more can information for the pas ecu? 

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1 hour ago, Benginetuner said:

Yes it currently has the stock rx8 ecu in place controlling the dash etc.

So how is the RX8 ECU getting an RPM signal?  Do you have an RX8 triggerwheel on the 1J as well?  Is the tacho on the dash working?

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According to the rx8 manual, the criteria & wiring for that code are independent of the ECU

image.png.4162bcd12b548412c4d7f308a661f473.png

It also says you should have 15 Ohms from a-b and b-c terminals of the torque sensor. Maybe its got a bad connection somewhere and it comes right once there is a bit of heat around?

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Thanks for the reply, I'll have a look and see what it is. 

 

I connected a code reader and checked the values of the torque sensor when turning the wheel from cold and they were within spec.  I didn't think to get the multimeter out. 

 

The odd thing is that when I had the stock 1jz ecu connected to engine it doesn't  do it. I will investigate.

I'm just thinking the only other thing that's different now is I've removed the jz maf sensor. That's pushed the air filter back a few inches so it's not sat over the pas ecu anymore. 

Screenshot_20190825_101140_com.android.chrome.jpg

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On 8/25/2019 at 7:24 AM, cj said:

According to the rx8 manual, the criteria & wiring for that code are independent of the ECU

image.png.4162bcd12b548412c4d7f308a661f473.png

It also says you should have 15 Ohms from a-b and b-c terminals of the torque sensor. Maybe its got a bad connection somewhere and it comes right once there is a bit of heat around?

I have 13.6 ohms between C and b from cold and 14 ohms between a & b at the eps ecu 

 

13.6ohms on both a&b and b&c at the rack 

 

It's between 12 and 15 ohms so all within spec 

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can you get a scan tool hooked up to it or some other thing that can display steering position/torque sensor output as the EPS ECU sees it? then go wiggling some wires between the torque sensor and the EPS ecu. if the sensor test ok, and you have intermittent (cold) errors thrown for it, then I'd be suspicious of wiring issues like corrosion in one of the connectors or a loose female side in one of them

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8 hours ago, cj said:

can you get a scan tool hooked up to it or some other thing that can display steering position/torque sensor output as the EPS ECU sees it? then go wiggling some wires between the torque sensor and the EPS ecu. if the sensor test ok, and you have intermittent (cold) errors thrown for it, then I'd be suspicious of wiring issues like corrosion in one of the connectors or a loose female side in one of them

I will, I'm at the point of trying anything. 

I visually inspected the connectors and the wiring and they all look good. I've got two eps ecu's that I've tried.

Using my toucan I've been turning the car on and off as I'm driving to get the steering assist to work. Coolant temp was showing 80'c for the assist to work. I may try and make something to cover the eps ecu up, as its currently bolted to the chassis on spacers. Like I said in an earlier post the foam air filter used to sit over it before I deleted the maf sensor. 

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On 8/30/2019 at 3:32 PM, Benginetuner said:

I will, I'm at the point of trying anything. 

I visually inspected the connectors and the wiring and they all look good. I've got two eps ecu's that I've tried.

Using my toucan I've been turning the car on and off as I'm driving to get the steering assist to work. Coolant temp was showing 80'c for the assist to work. I may try and make something to cover the eps ecu up, as its currently bolted to the chassis on spacers. Like I said in an earlier post the foam air filter used to sit over it before I deleted the maf sensor. 

Hey Benginetuner

did you ever work out what was causing the issue?

i have a fairly stock rx8 and have got power steering issues a week after switching my ecu, throttle body, radiator and fans. ive soldered all the connection plugs between eps motor and the control module. there is continuity where it should be. ive followed the troubleshooting guide to the point it says to replace the module and or rack (https://www.rotaryheads.com/PDF/RX8/8Steering.PDF). 

in mazda iDS datalogger i get perfect readings from the torque sensor like you did, the eps motor jumps from 0.00A to -1.00A and the torque sensor correction is stuck on 1.75Nm. i assume its the control module and have purchased one from overseas but thought id see if i could find anything else out in the meantime.

cheers!

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EPS.avi_snapshot_00.04.321.jpg

EPS.avi_snapshot_00.04.674.jpg

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