View Full Version : '99RR "Maximum 20MPH" suspension message.

12-11-2007, 05:00 PM
Hi all;

I've been battling an annoying message on our '99RR 4.0. First off, there are no suspension faults stored in the system (I have the Rovacom Lite (RCL)) and the suspension functions perfectly as far as maintaining standard height, lowering to highway mode, lowering to access mode, rising to high, etc. There are also no leaks.

The problem is that the truck apparently thinks it is in entry mode all the time because when I pass 20 MPH it flashes the "Maximum 20MPH" message". When slowing below 20 it disappears. This is NOT the hard or soft fault message, and again, it functions perfectly well and there are no error codes in the memory. Using the RCL I can see all the settings, height settings, valve states, etc and cannot identify anything out of spec. The only possibility is that once, several months ago, just playing with the RCL I received a "front left height sensor" fault message on the RCL but the instrument cluster was not displaying any EAS fault message. It cleared and I have never seen it again. The sensor is giving proper height info and I can watch the height settings rise and fall on the RCL screen while I'm manipulating the EAS. I've also used the RCL while driving and no fault code is present, even when the message is present on the instrument panel.

Has anyone heard of this problem before?

Is this possibly a bad ECU? I am going to try and swap ECUs with a friends truck, but he's out of town for quite some time.

Thanks in advance for any help.

Greg Haugen

12-12-2007, 06:04 PM
Thanks to several folks on other BB services for the correct answer. It wasn't related to suspension at all but I had inadvertently hit the speed limiter button. Boy do I feel dumb.