Car limited to 85mph - help!

[hass121]

Originally Posted by robrocketanski

There is one 20 amp fuse that powers the Suspension Control Module. If there is an actual problem then that won't help but it is a decent thing to try. Just disconnecting the battery will work well enough. But if the problem is still there then there is a fault.

Replacing the module calls for programming it too so you couldn't just get a new module, you would still need the GM tool to program it- SPS.

If the fault doesn't go away it is also possible that one of the 4 actuators or 4 sensors are bad, or the wiring for them. It really would be best to diagnose it correctly which would require scanning for DTCs.

That's a great help thank you. Just to confirm;

1) Ensure ignition etc is off.
2) Open boot and remove negative terminal
3) Then remove positive terminal
4) Touch them both together and hold for approx 15 seconds
5) Reconnect positive
6) Reconnect negative
7) Start the car

Is this the right way? I just dont want to do anything wrong because there is so little support out here. For the record, the chevrolet dealers in the UK only sell the smaller cars. I just rang one and she asked "what is the Camaro, is that an electric car?!"

[robrocketanski]

If you don't have the Service.... warning message on the DTC then I THINK (but not sure) that you should not have any of the DTCs and the problem should not be the module or the 8 other components. If it was then you would have that Service... warning message.

There are specific symptoms for any given failure. The procedure above is specifically for Suspension Control Switch Malfunction which is what you are describing.

[robrocketanski]

Those steps would be fine, no harm done.

My car did this exact same thing once but it went away after one ignition cycle.

[hass121]

Originally Posted by robrocketanski

If you don't have the Service.... warning message on the DTC then I THINK (but not sure) that you should not have any of the DTCs and the problem should not be the module or the 8 other components. If it was then you would have that Service... warning message.

There are specific symptoms for any given failure. The procedure above is specifically for Suspension Control Switch Malfunction which is what you are describing.

Absolutely agree with you - there are no warning messages whatsoever, just a very bouncy ride and 85mph limit that cannot be exceeded. I read on here that some members had the same thing but then it rectified itself. Sadly mine has not..... yet...

[robrocketanski]

We sell the Camaro there so there should be some dealers that know how to work on it. If the problem doesn't go away on its own it would be worth several hours of driving to get it diagnosed and fixed correctly.

[buffalobill]

Mine did this once over a year ago , it reset itself after a few starts and has never done it again.

[hass121]

Originally Posted by robrocketanski

We sell the Camaro there so there should be some dealers that know how to work on it. If the problem doesn't go away on its own it would be worth several hours of driving to get it diagnosed and fixed correctly.

Yes i will try the battery disconnect and then take it from there.... i certainly hope it sorts the problem....

[hass121]

Update - unplugged battery and touched two sides together. Had to reset windows etc but still no lights on comfort / sport buttons when car is started. Is this an indication that problem persists? Are those two lights supposed to show?

[redleader]

Where in the UK?

James [redleader] C5 UK

[robrocketanski]

One of the two lights should always be on. The procedure I pasted earlier is for the switch not working. It basically has you check all the wires to the switch, if they are all good then replace the switch.

[UKCamaro2SS]

Not sure if this helps, but last week I bought an SCT X4 tuner with a custom tune from the states, and one of the options when I flashed the ECU was the speed limiter which was set on 105mph which I of course set to no limit.

Point being it may be an ECU/tune Restriction.

Note: Mine is an SS, wishing it was a ZL1

[KaBoom1701]

Gezzzz...and I thought the US economy nannies were tough.......lol

[sterlingRPI]

Originally Posted by Slaughtz_ZL1

Try unhooking both terminals of the battery then touch them together for 2-3 minutes should clear the memory of the ECM

Unrelated question. But would that undo a dyno tune?

[Whos_Drivin]

Originally Posted by sterlingRPI

Unrelated question. But would that undo a dyno tune?

No, a tune changes tables/settings on the ECM. Kind of like changing an Excel file on PC, saving it, then unplugging your computer. When you go back in it will still be saved.

That said, I would never purposely short a system by touching two wires together. Just leave it disconnected over night.