SYS on display and speedometer and odometer stopped working

[ZuggZR1]

Today out of the blue the 1990 ZR1 threw the SYS error on the display and the Speedometer just said 0, as well as the odometer, did not work as well. The engine started to run higher than normal almost like a choke was stuck on and then would also run rough almost stalling. Any suggestions would be greatly appreciated.

Video of codes here https://www.dropbox.com/s/f3izumgdvl...sults.mp4?dl=0

[secondchance]

Is service engine soon light on.
Perhaps, start with pulling code?

[Hib Halverson]

Can't do much to help unless you can get the codes out of the various controllers memories.

Do you have a factory service manual for the car?

[Ccmano]

Originally Posted by secondchance

Is service engine soon light on.
Perhaps, start with pulling code?

Agreed, need to pull codes. My guess is the SES light is on too. You’ll probably find its VSS (Vehicle Speed Senor) related. Either the sensor itself (just had this on a friends car) or the related wiring.
H

[ZuggZR1]

here is codes on video https://www.dropbox.com/s/f3izumgdvl...sults.mp4?dl=0


Not sure what the Err is all about and then just hangs

[Ccmano]

Ok, C41 (with the 1 above) is a CCM code indicating “Loss of ECM serial data communications “ the H41 simply means it’s in history and has happened before. The ‘err’ (with the 4 above) means there was no communication with the ECM to get ECM fault codes.

Did you get any engine codes as well? Without a scanner you would need to use the “paper clip” method. Like this...
http://www.zr1specialist.com/HAT%20W...0Info/aldl.htm

Once you get any engine codes we will have a better picture. C41 codes can be tricky and it’s important to follow the diagnostic tree in the manual (page 8d-46 in the 90” manual). In this case it could be anything from a bad CCM module, a bad ECM, bad Memcal, bad connection to any of these or most likely an bad ground or short in the wiring.

Here’s an idea of the last thread on the subject. Turned out to be the Memcal. But that doesn’t mean that your issue.

http://www.zr1.net/forum/showthread....ht=Code&page=6

If your not at least somewhat competent in electrical diagnostic work its best left to someone who is. Otherwise you end up throwing parts at it (like many do), doing unnecessary work and spend much more money than needed.

This is not specific to a ZR-1, therefore any competent auto electrical shop should be able to handle it. Operative word here being “competent”. If you have any skills at all it might be best to tackle it yourself.
H

[-=Jeff=-]

Wait,

Did you say the odometer is showing 0 miles?
Can you change the LCD Display with the DIC buttons?

I am thinking this might be CCM related, in t e FSM there is a procedure to get into the CCM Diagnostics, might be worth doing and testing some of those functions.

But before we get too far ahead.. Check all the CCM related fuses (or all the fuses for that matter).. do this first

[chriskinzel]

When I got an SYS on my display it was a bad battery. Might want to start there.


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[ZuggZR1]

Battery was brand new in July so pretty sure not that

Sent from my SM-G975U using ZR-1 Net Registry mobile app

[-=Jeff=-]

Looked at your picture again.. that is the TRIP showing 0.. please confirm the Odometer is showing the correct mileage. You have a 1990.. my best guess, the VSS is bad.. You might have a hard time finding a 1990 VSS, the 1990 will work with a harness connector change