SYS light flashing.

[Z51JEFF]

I get this flashing at times but not constant.I checked for codes but none at present.Its been awhile since Ive used the A-B terminal trick but checked for codes and got a 12 which If I remember correctly is normal.Any clues?

[tf95ZR1]

Battery or connections.
I'm no expert, but this is what SYS has been
for me EVERY TIME.

[GOLDCYLON]

Battery or alternator. My best guess is battery

[scottfab]

Yup, battery. Mine did this both time before replacing it
twice in the last 15yrs.

[VetteMed]

A-B only displays ECM codes. SYS flashes when the CCM has a code stored.

[VetteMed]

Jump A to G to display CCM codes.

[scottfab]

Jump A to G to display CCM codes.

On a 90 you can get at the ECM codes from the CCM entery.
After in the CCM diag mode press TRIP RESET a few times till
you see 4.0. Then Press TRIP ODD a few times till 4.7 is displayed.
Press ENG/MET and hold till "---" is displayed.
You're there.

[GOLDCYLON]

Any update Jeff ?

[Z51JEFF]

Any update Jeff ?

Thanks for all the info guys.I put the charger on the battery for awhile,hope its not a loose cable at the starter:censored:If it persists Im going to do some digging and see what it is by doing the paper clip trick and the process with the buttons on the dash.Thanks again everybody for the info.

[Z51JEFF]

On a 90 you can get at the ECM codes from the CCM entery.
After in the CCM diag mode press TRIP RESET a few times till
you see 4.0. Then Press TRIP ODD a few times till 4.7 is displayed.
Press ENG/MET and hold till "---" is displayed.
You're there.

I got into the CCM and I get the ---,if there are no codes stored is this all I will see or is there another step I need to pull the codes?Im still getting the SYS flashing a few times when driving.

[scottfab]

I believe it is the TRIP REST button that cycles through the codes.
I'd have to go and try it to be sure.
Can't right now.

[Z51JEFF]

I believe it is the TRIP REST button that cycles through the codes.
I'd have to go and try it to be sure.
Can't right now.

Once I get into the system mode I tried pushing several of the buttons,one at a time of course and couldn't pull up a code or the --- never changed except to revert back to 4.1 or back to 4.7.

[scottfab]

Some of what I need to type here is in the manual. Some is not. It's stuff I discovered.
Like for instance if you use menu 1.4 you can cause cycle through many active diag mode that turns one thing on at a time like: oil change light, and all other dash lights, or door alarm bell, or (and be careful of this) the horn which just scared the crap out of me.

Anyway I made myself a little box that shorts out any two pins (not just the normal two) Not sure if that was in the manual.
The menus are 1.1, 1.4, 1.7, 4.0, 4.1, 4.4, 4.7, 7.0, 7.1, 7.7, and others.
4.1 is the ECM codes. ( I think the 4.7 one resets it)
1.1 is the CCM codes.

I am typing all this from memory so do check it against the manual. The page is 8D-8 according to what I wrote on my diag box.
Do you have a manual?

[Z51JEFF]

Some of what I need to type here is in the manual. Some is not. It's stuff I discovered.
Like for instance if you use menu 1.4 you can cause cycle through many active diag mode that turns one thing on at a time like: oil change light, and all other dash lights, or door alarm bell, or (and be careful of this) the horn which just scared the crap out of me.

Anyway I made myself a little box that shorts out any two pins (not just the normal two) Not sure if that was in the manual.
The menus are 1.1, 1.4, 1.7, 4.0, 4.1, 4.4, 4.7, 7.0, 7.1, 7.7, and others.
4.1 is the ECM codes. ( I think the 4.7 one resets it)
1.1 is the CCM codes.

I am typing all this from memory so do check it against the manual. The page is 8D-8 according to what I wrote on my diag box.
Do you have a manual?

I was able to get into the diagnostic mode and pulled up C12 which states there are no store code but with me pushing 4.7 I might have erased any stored codes.Thanks to everyone with the tips and info,much appreciated.

[Z51JEFF]

Finally got something,H13 which translate to left 02 sensor.Ive gone through the diagnostic process a bunch of times and while it doesn't always go through the process the stored code of 13 always comes back.

[scottfab]

Little Box connected to the ALDL that shorts out any two pins or combinations of multiple pins.......now that is a great idea. So....you have maybe ten or more switches on your box?

I used a rotary switch that grounds one of five connections. See page 8D-4 of the 90 MY manual.

Like rhipsher says.......ground various pins (your box with ten switches) and then turn on ignition key just before start and you will see a C12 followed by any and all suspect codes or you will see --- meaning there are no codes stored for that specific diagnostic (SRC, ECM. CCM....other).

Yes if no codes are set you see a C12 only. If you are in the CCM diag mode you see the CCM codes (if set) then after 3 seconds the next module is selected and codes for it are shown then the next module is selected and it's codes shown etc until all module are completed.
Shorting specific pins to enter just that module allows focus on that module only and to reset the codes while there..


rhipsher ALDL Pin grounding and code reading (http://www.zr1.net/forum/showthread.php?p=96626)

Then.......Clearing Codes:
With jumber in place to clear codes (your box with appropriate switch closed):

CCM codes, press Trip/ODO until 1.7 appears.
Press and hold the ENG/MET button until --- appears.

ECM codes, press Trip/ODO until 4.7 appears.
Press and hold the ENG/MET button until --- appears.

Once you have any combination of pins shorted out (1.1, 1.4, 1.7, 4.0, 4.1, 4.4, 4.7, 7.0, 7.1, 7.7, and others) you can run diagnostics.

This was incorrect. Actually using the switch you can enter the 1.0 and select 1.4 or 1.7 etc. Or using the switch select 4.0 and cycle through the others. etc for the other switch positions.

[scottfab]

You are saying if rhipsher kept going for another 3 seconds after seeing --- he would have entered say the CCM if he was in ECM? He would then get a C12 to start that CCM module?

From the initial 1.0 (CCM) switch position it will cycle to all of the other modules and there codes (if set) automatically.

You lost me.....when you say using the switch (your switch for ground pins?) how do you enter 1.0? and how do you select 1.4?[/B]


from the first position (CCM) you can use the TRIP REST to go to the other Modules (ECM, SIR etc) and the TRIP ODD to pick the sub part (x.1, x.2 etc) of that module. The x.7 being the code reset part.

[XfireZ51]

OK....I think I understand.....if I ground A to G (CCM) using a ground wire or your switch box (primary 1.0), I can then TRIP REST to go to other modules such as ground A to B (ECM) which is primary 4.0.

I then use TRIP ODO to pick up the sub part once in the primary with a TRIP REST. Once in the TRIP ODO I go to a X.7 to clear all codes in that primary category say (ECM if I am in Category 4.0).

I think I have it ;).....Maybe :D

Its actually easier than it sounds. Did this last year.

[ghlkal]

I used a rotary switch that grounds one of five connections. See page 8D-4 of the 90 MY manual. Does anyone have a scan of that page 8D-4 of the 90 manual and does that apply to the 91' also?


Here's figure 3 on that page with the pinout diagram.