Riddle me this no start issue
Thread Starter
Instructor
Joined: Apr 2022
Posts: 142
Likes: 48
From: Central NY State
Looked it up to 100% confirm… FSM, book 2, 8A-30-0 is the diagram. Nothing from the ECM at play….
Ignition switch, to clutch/crank fuse to clutch switch to starter relay. Starter relay is enabled/ grounded by the CCM via VATS enablement. Then from starter relay to starter solenoid.
To confirm security light is not ON when you try to crank?
My hot take: whatever ground the CCM is using is bad OR main block ground is bad…ground term/cable on batt bad…. Check Voltage between positive terminal and the block and chassis.
You will likely see no 12V at the solenoid of the starter.
Ignition switch, to clutch/crank fuse to clutch switch to starter relay. Starter relay is enabled/ grounded by the CCM via VATS enablement. Then from starter relay to starter solenoid.
To confirm security light is not ON when you try to crank?
My hot take: whatever ground the CCM is using is bad OR main block ground is bad…ground term/cable on batt bad…. Check Voltage between positive terminal and the block and chassis.
You will likely see no 12V at the solenoid of the starter.
Drifting
Joined: Jun 2020
Posts: 1,355
Likes: 396
From: Northwest Ohio
When you turn the key to run, the security light should turn off immediately. The CCM is not seeing what it thinks is the right resistance. No the relay would not impact that light/VATS. Your combined set of issues is very strange. It seems like a broken wire/bad connection(s) somewhere, you still need to thoroughly check and clean the main grounds and terminals. Again only the CCM is involved with the security light and the crank circuit. A CCM with a bad ground/poor voltage would potentially read the wrong resistance.
The VATS system is very simple: CCM reads the resistance of the key pellet when inserted into the ignition cylinder and turned to on. It’s a simple wire running from the ignition cylinder back to the CCM. If the CCM sees the resistance of the pellet it is looking for, the security light turns off, it grounds the starter relay and sends a signal to the ECM to enable the Fuel Injectors.
After you’ve made sure on connections, you need the FSM and need to troubleshoot VATS signal. Yes you can try to bypass VATS with a resistor spliced into the wires at the base of the column. Perhaps you are right and the vats key resistance wire or something in the ignition cylinder or column is broken. Trying the bypass resistor would verify this. Note that you aren’t really bypassing VATS just the key pellet in the ignition cylinder. To truly bypass VATS requires force grounding the starter relay and reprogramming the ECM to never disable the fuel injectors….so don’t go down this route…fix what you have (at worst stop at the bypass resistor).
Also if you haven’t tried it, try another key and clean the pellet before putting it into the ignition cylinder.
The VATS system is very simple: CCM reads the resistance of the key pellet when inserted into the ignition cylinder and turned to on. It’s a simple wire running from the ignition cylinder back to the CCM. If the CCM sees the resistance of the pellet it is looking for, the security light turns off, it grounds the starter relay and sends a signal to the ECM to enable the Fuel Injectors.
After you’ve made sure on connections, you need the FSM and need to troubleshoot VATS signal. Yes you can try to bypass VATS with a resistor spliced into the wires at the base of the column. Perhaps you are right and the vats key resistance wire or something in the ignition cylinder or column is broken. Trying the bypass resistor would verify this. Note that you aren’t really bypassing VATS just the key pellet in the ignition cylinder. To truly bypass VATS requires force grounding the starter relay and reprogramming the ECM to never disable the fuel injectors….so don’t go down this route…fix what you have (at worst stop at the bypass resistor).
Also if you haven’t tried it, try another key and clean the pellet before putting it into the ignition cylinder.
Thread Starter
Instructor
Joined: Apr 2022
Posts: 142
Likes: 48
From: Central NY State
When you turn the key to run, the security light should turn off immediately. The CCM is not seeing what it thinks is the right resistance. No the relay would not impact that light/VATS. Your combined set of issues is very strange. It seems like a broken wire/bad connection(s) somewhere, you still need to thoroughly check and clean the main grounds and terminals. Again only the CCM is involved with the security light and the crank circuit. A CCM with a bad ground/poor voltage would potentially read the wrong resistance.
The VATS system is very simple: CCM reads the resistance of the key pellet when inserted into the ignition cylinder and turned to on. It’s a simple wire running from the ignition cylinder back to the CCM. If the CCM sees the resistance of the pellet it is looking for, the security light turns off, it grounds the starter relay and sends a signal to the ECM to enable the Fuel Injectors.
After you’ve made sure on connections, you need the FSM and need to troubleshoot VATS signal. Yes you can try to bypass VATS with a resistor spliced into the wires at the base of the column. Perhaps you are right and the vats key resistance wire or something in the ignition cylinder or column is broken. Trying the bypass resistor would verify this. Note that you aren’t really bypassing VATS just the key pellet in the ignition cylinder. To truly bypass VATS requires force grounding the starter relay and reprogramming the ECM to never disable the fuel injectors….so don’t go down this route…fix what you have (at worst stop at the bypass resistor).
Also if you haven’t tried it, try another key and clean the pellet before putting it into the ignition cylinder.
The VATS system is very simple: CCM reads the resistance of the key pellet when inserted into the ignition cylinder and turned to on. It’s a simple wire running from the ignition cylinder back to the CCM. If the CCM sees the resistance of the pellet it is looking for, the security light turns off, it grounds the starter relay and sends a signal to the ECM to enable the Fuel Injectors.
After you’ve made sure on connections, you need the FSM and need to troubleshoot VATS signal. Yes you can try to bypass VATS with a resistor spliced into the wires at the base of the column. Perhaps you are right and the vats key resistance wire or something in the ignition cylinder or column is broken. Trying the bypass resistor would verify this. Note that you aren’t really bypassing VATS just the key pellet in the ignition cylinder. To truly bypass VATS requires force grounding the starter relay and reprogramming the ECM to never disable the fuel injectors….so don’t go down this route…fix what you have (at worst stop at the bypass resistor).
Also if you haven’t tried it, try another key and clean the pellet before putting it into the ignition cylinder.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
All good info thank you. Yes I have to check my grounds, then try a different key, I have two more. If that doesn't help, maybe I'll get a resistor after I read the key one to try and bypass the ignition cylinder and rule that out. Worst case I'll be digging into the dash to check wiring at CCM and under the dash.
Do you have two keys for the car? If so, you can drop the kick panel under the dash, access the VATS wires that run up the column to the tumbler. A free/fast test would be unplug the plug for that harness at the base of the steering column, install two jumper wires (into the CCM side of the plug), then rig a connection for each wire, to each side of the key pellet. Take your other key and try cranking the car...or just turn the key ro "Run" and see if the Security light goes out. If it does, the car will crank (unless there are other problems).
Thread Starter
Instructor
Joined: Apr 2022
Posts: 142
Likes: 48
From: Central NY State
At this point, you should "try a different key", AKA, diag the VATS issue. That's why it won't crank.
Do you have two keys for the car? If so, you can drop the kick panel under the dash, access the VATS wires that run up the column to the tumbler. A free/fast test would be unplug the plug for that harness at the base of the steering column, install two jumper wires (into the CCM side of the plug), then rig a connection for each wire, to each side of the key pellet. Take your other key and try cranking the car...or just turn the key ro "Run" and see if the Security light goes out. If it does, the car will crank (unless there are other problems).
Do you have two keys for the car? If so, you can drop the kick panel under the dash, access the VATS wires that run up the column to the tumbler. A free/fast test would be unplug the plug for that harness at the base of the steering column, install two jumper wires (into the CCM side of the plug), then rig a connection for each wire, to each side of the key pellet. Take your other key and try cranking the car...or just turn the key ro "Run" and see if the Security light goes out. If it does, the car will crank (unless there are other problems).
Yup the vats issue will be checked first. Tried different spare keys and no luck. I ordered a cheap VATs bypass resistor plug. I checked mine and my keys are 3740 ohms. So I’ll try that this coming week when it comes to rule out the ignition key wires broken. I also put a new PCV valve in with a new grommet and fabricated a new 180 degree hose from it with Dorman help Pcv hose parts.
Thanks for the thoughts and help so far. I get mad at this car, but when I go in the garage and look at it, I love it.
Instructor
Joined: Apr 2022
Posts: 187
Likes: 31
From: South Texas
[QUOTE=Riley93C4;1605872586]Yup the vats issue will be checked first. Tried different spare keys and no luck. I ordered a cheap VATs bypass resistor plug. I checked mine and my keys are 3740 ohms. So I’ll try that this coming week when it comes to rule out the ignition key wires broken. I also put a new PCV valve in with a new grommet and fabricated a new 180 degree hose from it with Dorman help Pcv hose parts.
Thanks for the thoughts and help so far. I get mad at this car, but when I go in the garage and look at it, I love it.
/QUOTE]
Corvette Fever: When your hobby turns into an obsession....
Thanks for the thoughts and help so far. I get mad at this car, but when I go in the garage and look at it, I love it.
/QUOTE]
Corvette Fever: When your hobby turns into an obsession....
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