My son and I recently did some work to repair the wiper switch in his 1990 coupe after the turn signal follower "rail" snapped off like has happened to so many. Once we buttoned everything back up, we are finding that the car won't start - no solenoid click and no starter noise. Battery is charged.

When we open the car door, the SECURITY light blinks slowly. When we turn the key to on, the security light blinks rapidly. I measured the resistance on both his keys and verified they seem good (1.871k and 1.865k). I pulled the connector for the wires going down the column from the lock cylinder and verified that when the key is inserted, I can see the same resistance there. This seems to me like it's a VATS issue, but I cannot figure out what else would need to be present for the ECM to be happy. Even if the starter enable relay was bad, I don't think it would flash security, right?

The only other small piece of the puzzle relates to the airbag. When we were putting things back together we found that during a previous repair at some point the airbag yellow wire had gotten pinched between the column bracket and the mount. We pulled the wire out and just left the connector disconnected - for fear of whatever might have become of the wiring inside. Is there anything in the computer requiring the airbag be plugged in to satisfy the VATS system?

Any help would be appreciated.

 

While in the column have you created an issue with the ignition rotation and the pawl/rack & rod to the physical ignition switch mounted to the column? Are the connectors to the ignition switch secured? If you jumper the starter at the starter can you create 'CRANK'?

 

Thanks for the quick reply. That is entirely possible. We did drop the column down and I could verify that I saw the switch actuator rod moving, so the "selector" is engaged at least, but that doesn't mean it's "indexed" correctly. Before I tear back into the column, however, I wanted to know if that would cause the security light to flash quickly somehow? I thought that would only happen if the VATS system wasn't seeing the resistor.

 

Do you have the FSM(Factory/Field Service Manual)? I believe 'SECURITY' would go solid/steady if it were VATS. Quickly flashing?

If you have the FSM research CODE 46 and also maybe Code 54 for CCM.

Car cranked, ran and drove until you did the column?

With the ignition ON ," the security light should
be "ON" for 2 seconds then turn "OFF." If the security
light stays "ON" greater than 2 seconds with the
ignition "ON," there is a VATS problem.

 

Are the SECURITY flashes in a group of 3, simultaneous with 3 SYS messages in the speedometer?
If = YES, Check the AIR BAG fuse. (Important, because this fuse powers the ECM.)

If it is VATS related, ie the key resistance circuit., the SECURITY light should be solid-on in RUN. Not "flashing."

Are the battery connections clean. tight, and 'good'? Have you attempted to jump the starter solenoid right at the starter to verify that the starter does crank the engine?

 

Just checked: 10A AIR BAG fuse is good. Battery connections are good and tight. I have not attempted to directly jump the starter solenoid, but I'm not hearing the fuel pump either when the key is turned to on, so like you mentioned I still strongly suspect VATS somehow.

 

WVZR1, I have the FSM and I agree. I've seen notes about the SECURITY light going solid on for 2 seconds, then OFF if the key resistance measures good. I have seen folks say things like "the light flashing just means the door is open" and that's definitely true to an extent: It slowly flashes when the door is first opened before the key is inserted. I have not found any other good references for what I'm seeing with the "fast" blinking security light (it's about twice the frequency of when it's just from the open door).

 

Are the quick flashes in groups of three? Is there also a group of three SYS flashes simultaneously?

Is the Service Engine Soon light ON with the key in RUN? << I don't think it is.

 

Ok. The ECM is NOT powering-up. The fuel pump will always run for 2 seconds and stop even if "VATS" is inhibiting cranking and fuel injector enable. (VATS does not disable the fuel pump.)

Can you use the onboard diagnostics to pull all the codes, please? It is in section 8D, or jumper A&G and turn key to RUN. Watch the speedo.

 

OK. Despite the fact that we charged it up recently, I put the battery charger back on the battery. It was reading 12.2V which is certainly low for a battery charged up less than 2 weeks ago. Maybe the battery is the whole root of this problem. With the charger connected, when I turn the key to run, I CAN hear the fuel pump cycle on when I'm sitting in the car. Still getting the fast-flash security light (no SYS light flashing in tandem and the flashes are not in groups of 3) I jumpered A&G on the ALDL and I see "C12" for module one and then nothing but dashes until module 7 which shows "Err." I'll let it charge up and then try it again with the charger still connected. Maybe the battery failed while it sat so long as we worked on the column repair. Thanks for the assistance so far.

Also: I don't see a service engine soon like in the driver information center when I turn the key to run. Could be the bulb is burned out I suppose...

 

There is no "Module 7" until 1996, and then "7" is the F45 ride control. Your opening post says "1990". Is it a 90? (1990-91 have Module 1 and 4. No others.)

If there is no SES with the key in run, the ECM is likely NOT powered up. (Highly unlikely that the bulb is "burned out".)

Check all the fuses electrically. Don't just look at them:

Turn key to RUN.
Ground your meter or test light on the shell of the cig lighter.
With the other lead touch the metal in the little holes in each fuse.
Power in both holes = fuse and circuit ok.
Power in only one hole = that fuse is bad.
No power in either hole = most likely that circuit is not powered. (Such as "TAIL" if the headlight switch is OFF.)

Here are the pertinent fuses for a 1990 for your symptoms:
A/C
CCM
ECM
CLUSTER
AIR BAG
LCD

With the key in RUN, there must be power present in both holes on all of the above listed fuses.

The CCM has 3 fuses: LCD, A/C, CCM.
The CLUSTER fuse supplies power to the SES light.
ECM and AIR BAG supply the "turn-on" to the ECM.

 

The car is a 1990, but the mileage on the odometer does not match the title, so I'm sure some previous owner replaced the CCM but didn't have the ability to program it correctly. Perhaps it was from a later year - thus the module 7 Error. It's a rainy day here at the moment, so it might have to wait until tomorrow, but I'll finish charging up the battery and then check all these fuses. When we parked the car a few months back and tore into the column to work on the wiper/blinker switch issue there were no real problems with the ECM. It would be a big coincidence if somehow there was a power supply / fuse issue to the ECM (unless some of that wiring passes through the column area. Nonetheless, I'll pull and test the fuses and then look for voltage along the power-supply path for the ECM.

 

UPDATE: I popped the battery charger back on this morning and while waiting for it to charge I checked all the relevant fuses listed. I've got voltage (~14V) on both sides of each - suggesting the ECM is powering up. I know there was a problem with the EGR relay for a long while (which would then illuminate the SES light) - to me, it seems possible the SES bulb in the DIC has burned out. But I guess we will see. I'm going to let the charger finish doing it's thing and try starting it once more afterwards. If it doesn't start then, I think I may have to drop the column and take a look at the actuation of the ignition switch (although I have to say that if it's correctly energizing the fuses when I turn it to "run," it seems unlikely that something's out of whack on that switch.

 

"Checking" costs nothing other than a few minutes of time. Guessing causes frustration. I agree with you that if the fuses are powered, there is nothing wrong with the ignition switch.

A 1990 ECM is under the hood, and easy to access, so try these two tests:
(When disconnecting and reconnecting connectors at the ECM, always be sure the key is OFF. You don't have to disconnect the battery.)
(There are little numbers alongside the cavities to ID the cavities, then use the wire color to verify you have the target cavity.)

Check the SES light:
Unplug the RED connector from the ECM.
Turn key to RUN
Jumper cavity 1 (brn/wht wire) to ground. SES light should be ON. If = YES, the bulb is good.


Check the 'ignition' power-up signal to the ECM:
Same RED connector.
Cavity 10 (pnk/blk wire).
Turn key to RUN
Check for the presence of 12 Volts with your meter. Should be YES.

 

Thanks for all of your help so far. I'm hesitant to mess with the ECM connections since my general experience with this vehicle is that every underhood piece of plastic and wire has become brittle and I'd like to disturb them as little as possible. We took the battery to Autozone and had it load tested and despite it's somewhat lower-than-ideal voltage when charged it tested out good. We put the battery back in and connected a remote starter switch between the battery positive lead and the start solenoid terminal and verified we were able to bump the starter. I'm now running fairly certain that I MUST have messed something up inside the column or with the connectors when reinstalling everything. I have one nagging question that I might test out, however: I know the ECM is powered through the air bag fuse. With the yellow air bag connector (labeled "deployment feed" in the schematic) under the dash prevent voltage from reaching it? I may try hooking that back up - potentially crushed wire and all - later before I tear back into the column. The FSM shows the circuit with "shorting bars" in the connector that should close when the connector is removed, but perhaps those have failed?

 

HI, how did you fix the wiper switch? Mine just broke. Thanks.

 

Basically, we removed the wiper switch and left it dangling in the car, then made up a cardstock template of the shape of the body of the switch. My son drew up a repair part in CAD modeled somewhat after pictures of a metal repair that a steering column shop does for folks who send in the switch. We printed it out on a 3D printer in ABS to hopefully tolerate the in-cabin heat. Then we drilled and tapped the switch body and glued/screwed the repair part in place. You can see a picture at the bottom of this thread:

https://www.corvetteforum.com/forums...ing-wheel.html

I don't yet know if I can recommend this method. It seems to work so far, but we have run into other issues and he hasn't really driven the car in a few months so I don't know how well it will hold up. If it seems like it will, I will put the part design on Thingiverse so people could 3D print their own.

 

UPDATE: I finally grew frustrated enough to just plug the yellow airbag connector back in despite worries about the potentially crushed wire. Airbag didn't deploy, so that's good. Car started up no problem after that. I've not seen this behavior documented anywhere in the FSM, but I guess if that circuit isn't completed the ECM won't allow the car to start? Maybe the "shorting bar" in the connector is worn out and didn't make contact. The security light still fast-flashes when the key is in run. It shuts off after the car starts. Maybe this could be caused by the CCM being replaced with one from a later year? Or the fact that it wasn't programmed properly within the 100 miles allowed?

 

In the FSM check the diagnostics for SIR 9J-A. Book 1. I didn't read the entire section but in the past(many years ago) I had done diagnostics by jumping A & K, and cleared codes in doing some repairs. Since you've got what you expect could be a failed wire issue maybe a read of those diagnostics will clear 'your mind'. Look at Chart A and you'll see yellow wire DERM to SER(Start Enable Relay) and Ignition Switch.

Has your CCM actually been replaced? I didn't recall you mentioning that.

**** Looking at the diagram you attached the only fuse that 'wasn't' mentioned to check for your initial diagnostics is the 'CRANK A/B' fuse that's under dash in AUX Box.

 

Thanks for the wiper switch intel, I appreciate it. I've never seen the fast flash SECURITY light deal but I can help a little - my 92 has what I expect is a replaced, unprogrammed CCM (mileage inconsistency after a reported swap) and it does not exhibit that. The only thing I can think of would be to cycle the alarm by triggering it and then shutting it off by unlocking the door with the key.