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The Purple wire at the OBD port does not go directly to any module. It goes to the two Star connectors as I shoed in the schematic. Every one of the 11 or 12 modules is connected to one or the other Star connector.
PS: Forget the Red circle in the schematic. That was from another Thread.
Are you connecting the Tech 2 to the port before you turn the ignition on? If not you will get a communication issue.
first thanks to all for the reply's. Being a Senior Citizen requires me to get all the assistance I can from this GREAT forum and its MEMBERS.
2nd I slept on it and this morning went out and just did a step by step walk thru the tech 2. IT WAS WORKING CORRECTLY ALL THE TIME, I JUST JUMPED THE GUN and went directly to CHASSIS directly and that is the only time I do not have communication.
I was able to run all the diagnostics this morning..lights, windows, horn, traction control,etc UNTIL I went to the chassis mode.
I thought all along since comments were made that chassis was where my info on the shocks would be I assumed ??? wrong by going there directly.
So, it appears the issue is with access to the chassis module. I will now have to ask for assistance on determining the loss of CHASSIS access, any wire schematic info (I have the FSM, just would like any page direction or specific tests/tracings/short cuts others have found useful), where the chassis module is located and method to trace problem. Still not finished with checking under car but will by noon, need it on the ground and available.
Might have been simpler to just delete the F45 and upgraded to the C6 Z06 shocks...
i hear you but would like to figure it out and get the communication issue to the chassis fixed, then see what the shock issue is first before I delete anything. its stock and would like to stay in that configuration if possible. I know is aging but still in good shape and running other than this recent issue.
[QUOTE=C4TOMCAT;1590652453]i hear you but would like to figure it out and get the communication issue to the chassis fixed, then see what the shock issue is first before I delete anything. its stock and would like to stay in that configuration if possible. I know is aging but still in good shape and running other than this recent issue.
I smell what your stepping in... I'm about as hard headed at getting something to work as well... for what it's worth... I wouldn't worry to much about the originality of the car as much, as just making it what you want it to be and if totally stock and original is what that is, cool. But, these car lend themselves to some mods that the purest cringe about that really are NO big deal... shocks, stereo, cat back exhaust, tires and rims to name a few...anyhow if your happy we're happy
Good luck with getting the No Comm fixed...
If you can communicate to other features and not Chassis it must be a Tech 2 interface issue. I have seen this before and went to a near year and was able to get in for similar but not identical issues. I am not the only one whose has experienced this. It should not be a car related issue in my opinion.
If you can communicate to other features and not Chassis it must be a Tech 2 interface issue. I have seen this before and went to a near year and was able to get in for similar but not identical issues. I am not the only one whose has experienced this. It should not be a car related issue in my opinion.
Try that and let us know.
Mr. Sam
oK, so just to be clear, try using 98 or 99 or maybe 96 and see what happen.
tom
1430 thurs. tried different years from 94 to 2003 with the same result...no comm when attempting to get into CHASSIS F1-CVRTD, so if anyone has some suggestions on where to start to resolve this issue please chime in. I am open to all comments....however remote. car is on the ground again for use, found no issues with any connections under the car...visual and connection wise anyway.
Not sure about "CHASSIS F1-CVRTD" but what I provided was:
Shock Solenoid Test – Chassis > RTD > Special Functions
Mr. Sam
Good Morning, the F1 is the function key on the Tech 2 to access the Chassis, the CVRTD is the F1 area controlled (I think) but since I cannot communicate I do not know what all is in it.
I did access it on the 94 vet but that was earlier this week and I have already forgotten that...its friday
will pursue later this weekend and read the FSM some more.
I figured that but didn't want to overlook anything. Forget the FSM, it will not help you resolve this.
Can you access any other Chassis function?
My only explanation would be that RTD has been deleted from the cars RPO so you get NO Comm when trying to connect. Do you even have the module in the trunk? If the connectors are disconnected and you reconnect them then if there is a problem with something you will get codes and an 80MPH limit. If that happens I can provide you the way to undo that.
Sorry, forgot you already have a message and MPH limit. Still think the ESC module is not powered, not grounded, serial bus wire issue, or bad ESC for No Comm to show up. That would prevent codes from being thrown but not prevent the message and speed limit.
I figured that but didn't want to overlook anything. Forget the FSM, it will not help you resolve this.
Can you access any other Chassis function?
My only explanation would be that RTD has been deleted from the cars RPO so you get NO Comm when trying to connect. Do you even have the module in the trunk? If the connectors are disconnected and you reconnect them then if there is a problem with something you will get codes and an 80MPH limit. If that happens I can provide you the way to undo that.
This is my best explanation for what is happening to you. Interested in what you find out.
Mr. Sam
What does RTD stand for, and where in trunk is it located, in the access doors. OOPS, after I wrote I realized REAL TIME DAMPENING! my mind is like a pin wheel trying to see all the option choices that could be causing this. if the RTD was not in the BCM...would I still get the messages of shock and mph???
Real Time Damping. However the module is called Electronic Suspension Control.
Should be in the driver side compartment in the trunk. Might be covered by carpet but should be on the side closest to the front of the car.
What does RTD stand for, and where in trunk is it located, in the access doors. OOPS, after I wrote I realized REAL TIME DAMPENING! my mind is like a pin wheel trying to see all the option choices that could be causing this. if the RTD was not in the BCM...would I still get the messages of shock and mph???
I reviewed some of my old favorites and I am going to look for grounds near that module just in case it is faulty. I did all the grounds shortly after getting the car in 2002...might me time to do again.
ok, looked at the reprogram...it is in there and I when I go to look at the special functions and have a list of the rf, lf, rr, lr items to activate when I pick one the tech 2 says establishing communications and I get a one second or less flash of items on the screen and then the no communication, key on/off message.
so it appears that momentarily there is a quick com connection but then lost. I will, as I stated earlier in a post, I will check grounds in that modules area just in case the quick connection and then loss is a ground issue. later out of pocket rest of the day.
You should not be getting the messages if the RPO for RTD is not "ON" in the BCM.
You need to look at what the BCM says and if you have the module and if you do is everything plugged in. Wasting your time chasing ghosts until you do that.
If you need to do diagnostics I can provide all the info on wiring and connectors.
You should not be getting the messages if the RPO for RTD is not "ON" in the BCM.
You need to look at what the BCM says and if you have the module and if you do is everything plugged in. Wasting your time chasing ghosts until you do that.
If you need to do diagnostics I can provide all the info on wiring and connectors.
ok, i pulled the ESC module from the LR TRUNK panel, all pins loo good.
Pulled the RTD relay out of the fuse panel by battery and ohm chedked it at 86.6 ohms, contacts NO were NO. I may try to figure a way to recheck the contacts in the panel this weekend to see if they close. by the ohms of the coil I suspect they will. I did find the circuit listing for the serial bus darK/blue wire and inspected for any issue and found none.
any way of verifying or identifying the info on the label, price, superceding data, updated or replacement items etc.
I only ask in case I need to change it but not there yet. wonder if the one in the 94, if same ????, would work as a test but sure do not want to damage th 97 system or the 94s esc since that car currently has no issues..I will pull it tomorrow maybe and compare....unless someone on the forum can confirm its good to swap with not damage potential.
enough for now....need to step back now and see if anyone has a solution to the Tech 2 having a momentary flash of the CVRTD screen data prior to the comm message. thanks all....although in a way this is fun, but only if you are reading this as a viewer, not the doer.
Throwing this graphic out to give you something else to look at. Its the ESC module wiring and serial data to STAR connector wiring.
Do you get a NO COMMUNICATION error on the DIC as well. If you do you most likely will get a NO COMM error in the TECH 2 as well. That flash is it probably trying to connect then see it can't then fail to NO COMM. You might have a bad module or serial to STAR connection issue or a Ground issue. People pull out the system but it is easy to see when you look at the module and the connectors have been pulled. Ground G402 manual says it is at "Transmission harness, RH rear of vehicle". Wherever that is exactly. Don't know what is with this graphic but there is a line going to battery positive "B1" on ETC but it does not show the line. Red wire going straight up to A on Underhood electrical center.
Last edited by RedRiderZR1; Oct 10, 2015 at 01:04 AM.
Throwing this graphic out to give you something else to look at. Its the ESC module wiring and serial data to STAR connector wiring.
Do you get a NO COMMUNICATION error on the DIC as well. If you do you most likely will get a NO COMM error in the TECH 2 as well. That flash is it probably trying to connect then see it can't then fail to NO COMM. You might have a bad module or serial to STAR connection issue or a Ground issue. People pull out the system but it is easy to see when you look at the module and the connectors have been pulled. Ground G402 manual says it is at "Transmission harness, RH rear of vehicle". Wherever that is exactly.
Redrider, I do not get a no com on the IP which has me baffled. you stated " is it probably trying to connect then see it can't then fail to NO COMM."...yes it does attempt to connect but only gives me the screen flash of a connection and then fails to no communication. I pulled the module and the connections on the ESC and the plugs are clean (I plan on double checking in the morning to be sure, I just did a quick look hoping to see some of Bill Curlee's bad ground type connections but they were clean....again at a quick look.
the relay you mention are you talking about the RDT relay that I measured at 86.6 ohms located in the engine fuse box by the battery that I posted the picture of.......or is there another one you are referring too. Too many thoughts to digest at this late hour, will look at it refreshed in the morning. thanks
