We were 900 miles into a 1000 mile trip when the power steering went out and a "Service Power Steering" message appeared on the DIC. ('17 Z51, 5900 miles). It happened as we drove onto an I10 on-ramp. The car drove like a pulp wood truck, except unlike a pulp wood truck I had brakes.

After arriving a our destination I took it the next morning to a dealer. Of course it was working properly when I took it to the dealer.

The dealer tech pulled the codes, it showed L056E and C056D. He indicated that means the whole steering rack needs replacing per Document #4213330 AOS.

Yes I've tracked the car a couple times before this trip and had no problems. It is tough driving with no power steering, but it can be done.

 

Sorry to hear. I bought a new '17 from Kerbeck's last September. Just as I got ready to leave on the 1600 mile trip home, the p/s totally died. No indication to me that it had thrown any codes. They determined it was a sensor that they could not readily replace so gave me an identical '18 for the same price and sent me on my way. Hence, apparently there is more than one reason for electric p/s to die entirely.

 

Back to the home dealer after another 1000 miles of driving. Power steering went out two more times on the return trip. It happened after 4-5 hours of driving at interstate speeds. I-10 to I-65 not much turning of the steering wheel, yet it went out. All three times it went out getting back on the interstate after stopping for gas. The new steering rack is on order. Amazing how quickly the conclusion came to replace the rack.

 

EPS can have many internal electronic failures (from all OEMs).

C056D and C056E are GM's "garbage dump" DTCs for EPS.

C056D means the electronic hardware had a failure. There isn't anything you can fix when that happens. You just get a new gear.

C056E means a software failure. This one typically is fixed by configuring the gear and flashing on a calibration. Sometimes this one is due to an internal software failure but that is unlikely.

The only EPS code that is fixable on a regular basis is C0545 which is a Torque Sensor issue. Usually its not the sensor but rather the cable from the pinion tower to the ECU. This technically can be spliced fixed, but I don't think GM allows it by default.

 

Got the car back today. Invoice says :C0545A Check for software updates per TAC Case. Replaced Steering gear as per TAC. Program PSCM and perform configuration procedure.
Check and set alignment.

All is good so far. We'll find out next Friday night at Charlotte Motor Speedway. (Night at the Track). There was a very faint whine that I didn't recall hearing before, but it went away after a mile. I guess everything had to shakedown.

 

Torque Sensor DTC. Betting it was a bad cable/sensor. Seems to be a few of these.

The whine is always there, when the system is new it's more noticeable. It's the belt from the motor to the ball nut (in the steering gear housing. It should sound like a zipper if you quickly move the steering wheel back and forth. Most belt driven EPS have that noise, the Bosch units are just some of the worst offenders of the noise.

 

How long did it take for dealer to get the new rack from when they ordered it?

 

The rack came in 2 days after the diagnosis. It took them 2 days to do the work. They had the car 6 days total and part of that was over the Mem day weekend.

I did a track day and everything seems fine. The dealer noted that toe had to be adjusted (expected) and the steering wheel is just a tinch off. Gotta fix that.

 

Do you know if rack is new or refurbished?

 

I have to take the air dam off the front, I'll look and see if there is any refurbished tag

update: didn't see any evidence it was refurbished.

 

May be applicable Safety Recall N182182760 on loss of EPS (electric power steering) details at https://my.gm.com/recalls

 

Same issues. Lost power steering several times but came back after about 30 seconds. I have a 2017 Z06 M7. Vin 606150, build date 04/17. This is a recent issue right at 10,000 miles.


UPDATE: Called Chevrolet and they said my car/trim was not included in the recall and that I would have to work through the dealership. They only gave me a complaint number associated with my call that I am supposed to give to the dealer when I take it in. Taking the car to the dealership today, 4/23/19, to have them look at it. Will update when with new information when I get it.

UPDATE: The dealership covered all the work under the bumper to bumper warranty. The dealership cost was $2,800. My VIN was not included in the recall for the steering gear assembly. The dealership said they looked at a nationwide database and saw that several 2017 Z06's had a similar problem and the steering gear assembly was replaced to resolve the problem. They ordered one, installed it and I have not had any issues out of it yet. I dropped the car off at the dealer on Tuesday April 23rd and had it back Friday April 26th.