Simple steering wheel off center? Not so fast

Brandon Technician Medina, Minnesota Posted   Latest   Edited  
Unsolved
Chassis
2015 Infiniti Q50 Sport 3.7L (VQ37VHR) 7-spd (RE7R01A) — JN1BV7AR0FM407417
Steering Off Center
Unable To Calibrate Dast
C1138 - 4Was Circuit

Hoping someone can point me in the right direction or provide some information. This vehicle was bought at auction and was previously repaired from a front end collision, it came in in rough shape. We completed our inspection and service on it, the only outstanding issue was the steering wheel. We sent it out for an alignment, we were told it's within specs, vehicle returned in the same condition. Prior to alignment, I tried to put the DAST system into auto adjust mode 1 and 2 and it would not adjust the wheel to center - I chalked it up to just actually needing an alignment. I have zero codes, zero driveability issues, full steering assist, no warning lights. 

I cannot get it to auto adjust for the life of me. Those unfamiliar with the procedure, you stop and restart the car, turn the wheel 90 degrees left and right 2 times, and drive straight between 19 and 25 mph for more than five seconds. Normally, this slowly brings the wheel back to center (according to the steering angle sensor). 

I tried recalibrating the SAS through the ABS module and it completes fine. SAS reads 0.0 straight ahead. I then tried to perform DAST Calibration (Mode 1) with our Autel MaxiSys Elite and a battery maintainer connected. It will perform 1.5 cycles, followed by a clunk in the steering column (I think the steering clutch is releasing) and our tool reports back "Command Impossible". This will intermittently set a C1138 - 4WAS Circuit code in the ABS module. The set criteria for the code is not helpful at all, basically "problem with steering system", check all connectors at the ABS and 3 DAST control modules. I went ahead and did that, they appear okay. All 3 modules appear original and undamaged, also in the correct locations (not swapped). I did not see any chaffed or misrouted wires like every other body shop car we've seen. At this point, I believe one of the position signals might be dropping out causing the calibration to fail, but I'm unsure what to monitor. The lack of codes before or after calibration failure are throwing me for a loop. I attached a video below of what happens.

I have access to ProDemand, Identifix, MaxiSys Elite, Pico 4425. Do not have a Consult III+ or Infiniti script. 

diag​.​net/file/f7bfix3w7…

This Infiniti TSB details the calibration process starting on page 17: [REMOVED DUE TO COPYRIGHT] PLEASE REFER TO SERVICE BULLETIN: SB…

Here is the SI for C1138: [REMOVED DUE TO COPYRIGHT] PLEASE REFER TO DOCUMENT: INFOID:… IN SI FOR DETAILS.

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Mark Manager
Boston, Massachusetts
Mark Default
 

GoodMorning Brandon , was the steering rack replaced ? We see many rack replacements were the steering shaft and the rack are not indexed correctly after replacement Car will be in alignment specs but the wheel will be off centered Good luck Mark

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Brandon Technician
Medina, Minnesota
Brandon Default
 

It doesn’t appear to have been replaced, all steering components appear to be original. I did check the steering shaft and it looks to be indexed to the rack correctly (there is a small green line that matches to the slot on the shaft). This vehicle is steer-by-wire meaning the steering wheel is physically disconnected (it has a clutch in the column) from the rack as long as the ignition is on…

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Rudy Technician
Montebello, California
Rudy Default
 

You need to try another scan tool before chasing your tail. Autel has come a long way and is a fantastic scan tool,but still falls short on many procedures it "claims" it can do.

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Brandon Technician
Medina, Minnesota
Brandon Default
 

I can only agree with you. If Nissan/Infiniti was more J2534 friendly I would've purchased a script after it failed the first time and tried that route, but they're too cost prohibitive for the amount we see needing factory software. I did as much as I could to confirm the system was functioning okay and sent it to the dealer for them to calibrate.

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Rudy Technician
Montebello, California
Rudy Default
 

Well, be sure to let us know if indeed it was simply a scan tool issue.

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Brandon Technician
Medina, Minnesota
Brandon Default
 

I indeed ran in circles because of a scantool issue. Dealer was able to calibrate the DAST without a problem.

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Rudy Technician
Montebello, California
Rudy Default
 

Thanks for the update. The message notification on this website is really horrible. If I wouldn't have been alerted to your post by email,I would have never known you updated.

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