'96 displaying "SYS" light ?

[gmhowe]

I haven't gotten to buying a service manual for my '96 I just got and was wondering what are possible causes for the "SYS" light flashing on the gauges ? Have noticed that the right door light being on very low though after driving it this evening ?

 

[gmjunkie]

I haven't gotten to buying a service manual for my '96 I just got and was wondering what are possible causes for the "SYS" light flashing on the gauges ? Have noticed that the right door light being on very low though after driving it this evening ?

Pull the codes and see what ya got,and go from there.

 

[KOPBET]

My experience has always been a bad or severely discharged battery.

 

[gmhowe]

Sorry GMJ but no "service engine soon" lite. It's on the display where the "avg Miles" guage is, they just keep swapping between themselves. Maybe take it down to Auto Zone for battery check.
As always thanx guys
Gordon

 

[jrp]

I haven't gotten to buying a service manual for my '96 I just got and was wondering what are possible causes for the "SYS" light flashing on the gauges ? Have noticed that the right door light being on very low though after driving it this evening ?

"SYS" indicates that one or more codes has been set in the CCM. Battery issues and aftermarket radios (they disturb the dimming circuit - mine does this but I haven't bothered to do the fix) are the most common causes that people post about, but there could be a fault in any of the systems that the CCM monitors or controls.

To be thorough, check codes as shown here: http://www.corvettebuyers.com/c4vettes/codes.htm

You'll need to scroll to the end to find the correct ALDL pins to jump for '96. Any codes that will flash "SYS" can be seen this way, but you must keep in mind that '96 is OBDII and that this method does not access the PCM codes (these set the check engine light) as suggested by that site.

 

[gmhowe]

It is not the "Service Engine Soon" light on the center console it is the "SYS" light alternates with the "avg mpg" display in the center of the main dash behind the steering wheel. It will flash 3 times then the avg mpg display comes back on for about 15 seconds then "SYS" again.

 

[marty.g]

i had the same problem. it turned out to be the charging system. the alternator was putting out 9 volts at battery. look in your owners manual and it will tell you it is in the electrical system. however i have an additional problem. the headlight motor on the right tries to keep turning till it stops. i have been told there are 3 plastic bushings inside that direct the stopping of the motor. i disconnected the battery for another purpose and when i connected it back the right light motor started motoring. this tells me i have a stuck relay. i'm having trouble locating the relays.

 

[gmjunkie]

i had the same problem. it turned out to be the charging system. the alternator was putting out 9 volts at battery. look in your owners manual and it will tell you it is in the electrical system. however i have an additional problem. the headlight motor on the right tries to keep turning till it stops. i have been told there are 3 plastic bushings inside that direct the stopping of the motor. i disconnected the battery for another purpose and when i connected it back the right light motor started motoring. this tells me i have a stuck relay. i'm having trouble locating the relays.

Relay is on the front of Lt front inner splash shield!!Black box about 3x4 inches,But it's probly not bad!! Replace the bushings in headlights and it will be fine!!

 

[gmhowe]

Dash shows its putting out 16 amps on the guage and no problems with the headlights, but as in my previous replies, at night I notice a faint orange glow from the passenger door lite, not real bright but noticeable.

 

[gmjunkie]

Dash shows its putting out 16 amps on the guage and no problems with the headlights, but as in my previous replies, at night I notice a faint orange glow from the passenger door lite, not real bright but noticeable.

Check the grounds,your back feeding somwhere!!

 

[gmjunkie]

It is not the "Service Engine Soon" light on the center console it is the "SYS" light alternates with the "avg mpg" display in the center of the main dash behind the steering wheel. It will flash 3 times then the avg mpg display comes back on for about 15 seconds then "SYS" again.

Run the Codes!!!There are more systems than just the engine!!!If the SYS light is coming on there are codes somewhere!!!!

 

[marty.g]

that i believe is the isolation relay. according to the manual schematic there 2 relays pluss the isolation relay. after i disconnected the one you are discribing there is still a draw on the battery. that's why i have to locate the other 2. especialy the right. thanks for your input i hope i have helped you on the SYS flashing

 

[KOPBET]

It will flash 3 times then the avg mpg display comes back on for about 15 seconds then "SYS" again.

Jumper DLC pin 12 to 4 (gnd) and turn on the ignition (no start) to begin the CCM diagnostic code display. The "MPG" area of the console will display the CCM module under interrogation and change from 1, 7, 9 and A while displaying either a DTC code or three dashes (---) in the "speedo" section.

Tell Junk what the code is so he can get you fixed up.

 

[jrp]

It is not the "Service Engine Soon" light on the center console it is the "SYS" light

The procedures in the website I posted will retrieve the codes which the SYS message is alerting you to. The text covers all years, so you'll have to scroll to the end for 1996.

For the earlier years, it also applies to the ECM codes signalled by the "Service Engine Soon" light, which is why it is mentioned at the beginning of the article.

 

[KOPBET]

The procedures in the website I posted will retrieve the codes which the SYS message is alerting you to. The text covers all years, so you'll have to scroll to the end for 1996.

For the earlier years, it also applies to the ECM codes signalled by the "Service Engine Soon" light, which is why it is mentioned at the beginning of the article.

Although the info for the 96 is not entirely correct.

 

[jrp]

Although the info for the 96 is not entirely correct.

...as pointed out when I first posted it.

It's hard to find concise information for 1996, because the service manual itself is misleading on the subject.

keep in mind that '96 is OBDII and that this method does not access the PCM codes (these set the check engine light) as suggested by that site.

 

[KOPBET]

...as pointed out when I first posted it.

Any codes that will flash "SYS" can be seen this way, but you must keep in mind that '96 is OBDII and that this method does not access the PCM codes (these set the check engine light) as suggested by that site.

That's not the part I was referring to as being incorrect.

 

[jrp]

That's not the part I was referring to as being incorrect.

So give a little more detail & educate us then. I'd like to know what I missed. I have retrieved "SYS" codes that way in the past (with the FSM for reference) and it worked out fine.

 

[KOPBET]

I have retrieved "SYS" codes that way in the past (with the FSM for reference) and it worked out fine.

Assuming you understand the difference between ALDL (GM only) and DLC (OBD-II). In that case, you have probably never seen an ALDL on your '96 or later Vette.

I would also bet you've never seen the CCM module number displayed in the trip odometer. CCM input and output status ID codes are displayed there, but only in manual mode.

There will always be at least one code displayed (C12) in automatic display mode. Even if there are no stored codes.

Module 4 is indeed the PCM. Fine. But PCM codes will not be displayed in the CCM diagnostics in either automatic or manual mode, so calling out module 4 in CCM diag references is non-sequitor.

 

[jrp]

Much better & good to know. Other than the last item, those are easy to overlook without the FSM in hand.