I did a search on the forums and couldn't find the exact issue that I'm having so I'll through it out there and see if anyone can help. I have a 09 Z06(stock) that seems to have an intermittent issue that causes the Service Vehicle Soon message to be displayed. While the message is active, my steering wheel becomes harder to turn. The first time I had this issue it lasted about 4 days. I can't get into the local dealership as usual when the error message is displayed.

Any thoughts or help greatly appreciated.

UPDATE - Looks like it was the EBCM Module. Shop tried to get the part covered on warranty since it only has 15000 miles but no luck. Going to cost around $600 to fix.

 

it should set an error code which the shop can read (doesn't need to be showing)

 

Had Autozone scan it with the service vehicle soon message still displayed and it still showed no codes. Found a local shop that is going to look at it tomorrow morning. Whatever the issue is there are no codes being stored.

 

Only a tech II can read every code the car will set. The auto zone reader might not have had the code in its bank.

 

Yeah, the shop I'm going to take it to has a reader like the dealership so hopefully they can shed some light on this issue. Would prefer the dealership, but dealing with them at times is like asking for trouble. My last visit ended up with my Z getting hit by one of the techs.

 

Keep us updated on your progress, IronFather. We're happy to help in the process of working with a dealership if you do eventually decide to go that route, as well.

Sarah (Assisting Evan), Chevrolet Customer Service

 

Thanks. The Service Vehicle Soon message cleared Saturday morning so the local shop told me to wait till it showed up again and they would look at it. Sunday morning rolled around and the message was back and my steering wheel was harder to move.

For giggles I disconnected the battery for a few minutes and the message was gone and my steering was back to normal. Guess I'll wait and see if it pops up again and drive straight to a shop and see if this issue can be troubleshot.

 

As has been noted by others above, a cleared code (one's that clear themselves......not ones you clear) can still be read. They are stored as history codes, so they are still in the computer. My shop has used these history codes to track down problems. The question is which computer......there are several in a C6. It could be in the PCM, BCM or elsewhere. That is why you need to have it scanned by a Tech II or equivalent.

BTW, the simple OBDII readers (probably what Autozone used) only read emission related codes in the PCM, so again it is important to scan with a Tech II or equivalent.

BTW2, I have a 2005 that did soemthing similar with steering that would get very very hard to turn at times (typically at low speeds), but it did not set any codes. Eventually I heard a light "snap" or "pop" come from the engine bay and it immediately returned to normal feel. It has been fine every since. When I looked in the engine bay I noticed that the engine block heater cord had come adrift and was laying across the steering shaft and one part of it had touched the exhaust manifold shield. The steering shaft also runs very close to the exhaust manifold, which means it gets quite hot too. My suspicision is that the heater cord got stuck to the steering shaft and the pop was it being pulled off when I turned the steering wheel.

 

Yes, OBD-II readers only read emissions related codes. But in your case, the problem is obvious: it's the power steering. I think the unit in our cars is fully mechanical, meaning you'd never see any codes: it's either the rack or the pump. If we have electronic variable assist, then it has to be the rack, computer that controls it, or the wiring (plus as mentioned, there should be some codes somewhere). Hopefully somebody can start by telling us if it's fully mechanical or not. Good luck.

 

As I recall, our cars has speed-sensitive power assist (lighter steering at low speeds. heavier at high speeds) so there is likely a computer and electrical involvement somewhere in the system.

Must confess I do not know much about the details of the power steering systems in our cars.

 

Thanks for the input folks. I drove the car to work and back today and had no issues with the message or steering. I did a search on google and found that my issues are shared by some other Vette owners. The only problem was there was no mention of resolution I could find.

I will keep am eye on it and update this post if the issue pops back up(and it will) and I am able to get in the shop for troubleshooting. I do believe it is an electrical issue.

 

My code reader can do ABS, OBD II and CEL codes. There hasn't been an issue with my car it wont couldn't detect but that being said there are codes that wont stay in the system. The ABS codes that enable the 'reduced engine power' wont stay in the system unless the car is in reduced engine power mode. My car has had a long history of randomly throwing out those codes since it was new and the dealer could never pull a code afterwards. Once I bought my code reader I could plug it in and read anything as it occurred.


Now when you say the car gets harder to turn does it feel like the power steering is completely gone or just slightly less helpful? I would almost agree with the electronic steering assist turning off. It helps when you're in a parking lot area with sharp turns and provides a harder feedback when you're driving at speed.

 

The power steering feels harder, but still assisted. That seems to be the only issue while getting the Service Vehicle Soon message.

 

Here's a description of the VES system in the C6. This is from my 2006 Service Manual, but my 2010 SM has the exact same wording:




You can see that there are a bunch of inputs to the EBCM, and the EBCM puts out a variable current to the actuator that controls the steering effort:
Then the EBCM sends a polarized current to the actuator based on those inputs in order to adjust the amount of steering assist.

It says that "voltage and ground are provided through the EBCM".

One of my first attempts to solve IronFather's problem would be to check for a solid ground.

Good luck, and keep us informed of the outcome so future problems like this might benefit from your experience.

Bob

 

Thanks for the info brother! Hopefully when I get a day off I can get this issue looked into. Will reference the info you provided. Thanks!

 

Updated in original post.