Dash Lights issue 99 Blazer LS

[TonyMazz]

Originally Posted by blazee

Thanks for the update Tony.


Have you asked them if they plan on making one that you can connect to a laptop and see real time data?

No I haven't recieved a response...but they DO have a Software Developers Kit interface for download on their web site.

So far the new v1.511 firmware upgrade works perfectly after 130 miles....I am going to leave it on and see how it goes...

This thing is handy and is how I actually diagnosed that my thermostat was keeping motor at 179-188 degrees......MPG went down....so I swapped out and got it back up to 194.7-195 range and mpg went back up....was only a minor change on the dash gauge.....

Blazee...I will ask again on the interactive portion.....and keep you updated..

Update - Reply back from Davis is that they have no immeadiate plans for interactive interface with car computer in the near future. The SDK interface only allows modifications to the existing 23 parameters not adding any new ones.....

[Schrade]

Hey JoulesW...
I'm not exactly sure what the solenoid is... I haven't seen a parts schematic yet. Nor can I take the credit, so here's a copy of another post pertinent to the problem...

The ignition switch causes shift problems, because it doesn't supply power to the tranny on circuit 1020. The same problems can be caused by an aftermarket remote start that was either connected wrong, or has developed a broken connection causing it not to energize circuit 1020 when the device is used. A problem with the remote start is easily diagnosed, if the problem occurs only when the remote start is used and functions normally when started by the key. A problem with the ignition switch or remote start not supplying power to circuit 1020 will set one or all of the following codes: P0740, P0753, P0758, P0785, and P1860. This condition will put the tranny in "limp home mode". This mode raises fluid pressure to maximum causing hard shifts when going into reverse and hard 1-2 shifts. After the initial shift into 3rd the tranny will stay in 3rd regardless of speed, this includes take-off. Taking off in 3rd can easily be mistaken as a loss of horsepower or tranny slippage. Leading you to believe the damage is far worse than just a simple loose wire. That is how some people really get screwed by tranny shops.

That was the end of the post. It said nothing of the guage lights, but when I cleared my DTC codes by unpluggin' the battery, all the problems went away, until the switch shorted again. The switch (not the keyed lock cylinder, but the under-column switch, which is activated by the turned key, is what's faulty.

[Schrade]

Hey JoulesW...
I'm not exactly sure what the solenoid is... I haven't seen a parts schematic yet. Nor can I take the credit, so here's a copy of another post pertinent to the problem...

The ignition switch causes shift problems, because it doesn't supply power to the tranny on circuit 1020. The same problems can be caused by an aftermarket remote start that was either connected wrong, or has developed a broken connection causing it not to energize circuit 1020 when the device is used. A problem with the remote start is easily diagnosed, if the problem occurs only when the remote start is used and functions normally when started by the key. A problem with the ignition switch or remote start not supplying power to circuit 1020 will set one or all of the following codes: P0740, P0753, P0758, P0785, and P1860. This condition will put the tranny in "limp home mode". This mode raises fluid pressure to maximum causing hard shifts when going into reverse and hard 1-2 shifts. After the initial shift into 3rd the tranny will stay in 3rd regardless of speed, this includes take-off. Taking off in 3rd can easily be mistaken as a loss of horsepower or tranny slippage. Leading you to believe the damage is far worse than just a simple loose wire. That is how some people really get screwed by tranny shops.

[JoulesWinfield]

So what wire supplies circuit 1020?
My truck totally died on the way home yesterday.
After I got a jump I made it home and checked the alternator by removing the battery ground and it seemed to work fine. Also I checked all the larger wires on the ignition switch and they were fine.
Not sure what to do now. The fuse is blown for the guages. But why? When I put in a new one everything seemed to work.

[blazee]

Joules,
The post that cbec1999 is quoting is one that I posted for someone having tranny problems. Circuit 1020 is the tranny circuit. You only need to worry about it if you are experiencing tranny problems.

A faulty ignition switch can cause problems with anything that is routed through it. Which is basically almost everything. Some things can function normally and others be totally screwed up. The most common problems are tranny problems, flickering gauges, random misfires, stalling, and the starter not engaging while attempting to start the engine.

If you start your own thread, we can help you there. It isn't nice to hi-jack Tony's thread.

[blazee]

Originally Posted by TonyMazz

Update - Reply back from Davis is that they have no immeadiate plans for interactive interface with car computer in the near future. The SDK interface only allows modifications to the existing 23 parameters not adding any new ones.....

Thanks.

You can still only monitor 4 parameters at a time...right?

[TonyMazz]

Originally Posted by blazee

Thanks.

You can still only monitor 4 parameters at a time...right?

yep....and some of the 23 parameters available on the chipE/X are not supported by the Blazer ECM. I am still experimenting on which ones....

The good news is they have dramatically improved the software interface where you can graph / compare by trip various parameters between trips etc.....

[JoulesWinfield]

Sorry, no hijack intended.
I was just wondering about the "solenoid".

[Schrade]

Thanks for the TSB schematic!
You said to TMazz that circuit 1020 controls only tranny functions. Could be. BUT... my Chilton's (which I question sometimes) shows 'instrument cluster' on the same circuit as 'tranny range switch', and transfer case control module'. So are you sure that 1020 controls only tranny functions?

[blazee]

It supplies other things, too. I never said it only controls tranny functions. I said it is the tranny circuit. It is one of the many circuits supplied through the ignition switch. If the switch doesn't supply power to it nothing on the circuit will work. If the tranny doesn't have problems then the circuit is fine. Why are you having such a hard time understanding this? I have answered these same questions for you repeatedly in several threads, I have told you the same thing in the emails you keep sending me, and I've even sent you a TSB with all the info. What seems to be the comprehension problem? You took what I said out of one thread where it was relevent, then copy and pasted it in about 30 different threads. Now I have 2 dozen people sending me PMs wanting me to explain it to them and it has nothing to do with their problems. Quit posting shit that you don't understand. NOT EVERY TRANNY PROBLEM IS CAUSED BY THE F*CKING SWITCH!

[rasmith527]

When you find out, PLEEEEEEASE let me know. My 98 Blazer is doing the same thing and I have no clue as to the problem. I'm not sure if it is a common problem. I didn't see many threads about it.