EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Flight Crew Returned To Gate; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
We got on the aircraft and performed all necessary checks.  2 passenger seats INOP; besides that no operational MELs.  Push backed normally and performed Before TAXI check.  Important to note that at this point EICAS was clear of any messages. I always make it a habit of calling for the Before Taxi Check only after I've confirmed on the EICAS that the tiller has engaged and STEER OFF message has cleared.  As I began taxiing; I noticed the airplane started veering left of centerline. I used the tiller to correct but realized that the airplane was not responding to my tiller input.  I used rudder input to stay on centerline and immediately looked at the EICAS; STEER OFF message was displayed.  I tried engaging the tiller numerous times to no avail.  Message remained.We stopped and set the parking brake.  We advised GRND of the situation.  They advised our operations at that time.  I called for the STEER OFF QRH.  It was a crew awareness message. I then called for the Mechanical Irreg Chart.  We decided we would be returning to the gate. We decided it would be best to call our ramp crew back to the airplane as we were blocking a very busy taxiway as well as the service road.  The Ramp Crew was already on the way.  I then asked my First Officer to coordinate with OPS for a gate.  The Ramp Crew came out to the aircraft and did something by the nose wheel.  The message disappeared on the EICAS and I could feel the tiller engage.  They signaled us to move the tiller.  It was operational.  Approximately 1 min later the STEER OFF message appeared again on the EICAS with no action by me.  And once again; I was not able to engage the tiller.  Ramp Crew was asking us if we could taxi by ourselves.  I made a decision based on how intermittent the issue was and erring on the side of caution to be towed back to the gate as there was already a super tug standing by.  MY First Officer advised GRND and OPS; and stayed on frequency with City Operations.  I made a PA to the passengers explaining the nature of the issue.  I then [sent an] ACARS to dispatch and asked them to have Maintenance meet us at the airplane.  They were standing by when we arrived.  They tried to troubleshoot the problem; and decided to do a HARD reset for 10 minutes on the airplane.  Between the First Officer and I; we were constantly making announcements in the back.I asked the flight attendants to do a snack and beverage service while we waited.  I also told the passengers that if anyone wanted to get off the airplane; we'd be more than happy to accommodate them.  They all opted to stay on board.  We decided to request more drinking water and fuel; as we were running low on both.  Maintenance did and operational test with the tiller; it worked fine. They signed off the logbook.  We waited on FUEL for a considerable amount of time; approximately 5 calls were made.  Finally we received it and pushed back.  Tiller worked fine both on departure and arrival.  This is a tough scenario to make any suggestions for.  It was not something we could have avoided in my opinion.  The First Officer and I discussed in detail the fact that we both looked at the EICAS during taxi out to ensure the steering message was not there.  I wanted to rule out any chance of pilot error.  The fact that I could not engage it even after recognition as well as it disengaging on its own for the second time confirmed to both of us that it may be an issue with the switch possibly.  We worked very expeditiously to ensure we got out of the taxiways as we realize how much of a problem that can be.
EMB-175 Captain reported returning to the gate area for maintenance when the nose wheel steering malfunctioned.