Confused and looking for pointers
Thread Starter
5th Gear
Joined: Oct 2021
Posts: 5
Likes: 0
From: Charleston SC
Confused and looking for pointers
So long story short,
my 93 6 speed convertible base model had a lower than normal idle (for it) on Wednesday. I drove home from work and it stalled on me. When I tried to restart the engine everything was normal except when the key was switched to “on” I didn’t hear the fuel pump prime the system. Turning further to “start” does nothing at all. No clicking from the starter, the engine doesn’t attempt to turn over. The security light stays solid illuminated and the climate control lights go out but the rest of the interior stays active and on.
diag codes only read c12. The initial reading showed H53 but once I cleared them the only code c12 (claiming normal operation).
I checked just about every fuse, all the grounds, all the wires in the engine bay and up under the dash. I tried 2 different keys, (normal original key and a rarely used spare). I got a new battery as the other was about 3 years old.
before I throw more money randomly at this issue I am wondering if I’m at least on the right track. Could it be Vats? Or is it possibly electrical gremlins? If the starter went bad wouldn’t it make a clicking noise at least?
in short…. HELP! 😂😂😂
my 93 6 speed convertible base model had a lower than normal idle (for it) on Wednesday. I drove home from work and it stalled on me. When I tried to restart the engine everything was normal except when the key was switched to “on” I didn’t hear the fuel pump prime the system. Turning further to “start” does nothing at all. No clicking from the starter, the engine doesn’t attempt to turn over. The security light stays solid illuminated and the climate control lights go out but the rest of the interior stays active and on.
diag codes only read c12. The initial reading showed H53 but once I cleared them the only code c12 (claiming normal operation).
I checked just about every fuse, all the grounds, all the wires in the engine bay and up under the dash. I tried 2 different keys, (normal original key and a rarely used spare). I got a new battery as the other was about 3 years old.
before I throw more money randomly at this issue I am wondering if I’m at least on the right track. Could it be Vats? Or is it possibly electrical gremlins? If the starter went bad wouldn’t it make a clicking noise at least?
in short…. HELP! 😂😂😂
Team Owner
Joined: Sep 2003
Posts: 25,366
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Do you have the FSM - Factory Service Manual for your car? DTC 53 diagnostics are there! Solid 'SECURITY' hints a VATS event of 'sorts'! Diagnostics - it's all about correct diagnostics!!
The DTC 53 generally thought to be an issue with the ignition cylinder. If you know the correct resistance of your keys many people would first insert a correct value resistance resistor in the connector near the lower column. If you elected to replace the cylinder then your current keys would be 'trash'!
The DTC 53 generally thought to be an issue with the ignition cylinder. If you know the correct resistance of your keys many people would first insert a correct value resistance resistor in the connector near the lower column. If you elected to replace the cylinder then your current keys would be 'trash'!
Last edited by WVZR-1; Oct 2, 2021 at 10:13 AM.
Thread Starter
5th Gear
Joined: Oct 2021
Posts: 5
Likes: 0
From: Charleston SC
Do you have the FSM - Factory Service Manual for your car? DTC 53 diagnostics are there! Solid 'SECURITY' hints a VATS event of 'sorts'! Diagnostics - it's all about correct diagnostics!!
The DTC 53 generally thought to be an issue with the ignition cylinder. If you know the correct resistance of your keys many people would first insert a correct value resistance resistor in the connector near the lower column. If you elected to replace the cylinder then your current keys would be 'trash'!
The DTC 53 generally thought to be an issue with the ignition cylinder. If you know the correct resistance of your keys many people would first insert a correct value resistance resistor in the connector near the lower column. If you elected to replace the cylinder then your current keys would be 'trash'!
would it be a good idea to insert a key and see if the same resistance reads at the connection under the steering column? If it doesn’t that would indicate the ignition cylinder is no good or am I wrong?
Team Owner
Joined: Sep 2003
Posts: 25,366
Likes: 2,733
I purchased an electronic version of the 1993 corvette fsm, the H53 pointed to vats. With it being a H (history) code, I cleared the code and attempted to start again, when it didn’t turn the second time I did the paperclip again and this time only get c12 in module 1 and no other codes. I tried a known working spare after about 10 minutes. Same thing. I tested both keys with a volt meter and both read @ or with in range of #11 being 4750. The key I use daily read 4660 and the guide gave minimum 4560 and maximum of 4960 so I’m leaning towards the keys not being the problem.
would it be a good idea to insert a key and see if the same resistance reads at the connection under the steering column? If it doesn’t that would indicate the ignition cylinder is no good or am I wrong?
would it be a good idea to insert a key and see if the same resistance reads at the connection under the steering column? If it doesn’t that would indicate the ignition cylinder is no good or am I wrong?
See 8D-7 for procedures.
Last edited by WVZR-1; Oct 2, 2021 at 11:11 AM.
Thread Starter
5th Gear
Joined: Oct 2021
Posts: 5
Likes: 0
From: Charleston SC
If you have the FSM there's a procedure that you can compare the A/D counts of keys and see what the CCM sees. See and read the 8D Section of the FSM! Yes you can check the resistance at the lower connector but yours was a 'random' so there's no assurance that it won't reoccur! If you use the 'tilt' function of the column excessively it could be wires at the cylinder are the cause or poor contacts. Use the A/D count procedure in the FSM. Read the diagnostics for the DTC 53.
See 8D-7 for procedures.
See 8D-7 for procedures.
still have not gotten my hands back on a multimeter as my friend that has it had some family stuff to do today. It’s my daily driver and has never given me any issues since I had the entire ignition system replaced last year along with the entire cooling system.
Thread Starter
5th Gear
Joined: Oct 2021
Posts: 5
Likes: 0
From: Charleston SC
just figured a video of what is seen / heard (or better yet not heard) during the start up process would help to verify a few things. 🤷🏻♂️
Thread Starter
5th Gear
Joined: Oct 2021
Posts: 5
Likes: 0
From: Charleston SC
Update, tested volts at all the major power connects throughout the car and all tested at 12v or 11.8v (fluctuating up to 12v), jumped the starter posts and starter engaged and tried to crank the car. Found a local electronics shop and bought 4.7k ohm resistors and tried “bypassing” vats by completing the circuit with the resistor in the lower leads and still no turn over.
verified all fuses are intact, at this point is it possible that my ecm could be the culprit?
the electronic service manual I have seems to not have a troubleshooting section but just consists of all the diagrams of all the vehicles systems and parts.
I would assume if the ecm is no good that other things would be acting up as well not just mimic of a vats security lockout.
verified all fuses are intact, at this point is it possible that my ecm could be the culprit?
the electronic service manual I have seems to not have a troubleshooting section but just consists of all the diagrams of all the vehicles systems and parts.
I would assume if the ecm is no good that other things would be acting up as well not just mimic of a vats security lockout.
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Team Owner
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Update, tested volts at all the major power connects throughout the car and all tested at 12v or 11.8v (fluctuating up to 12v), jumped the starter posts and starter engaged and tried to crank the car. Found a local electronics shop and bought 4.7k ohm resistors and tried “bypassing” vats by completing the circuit with the resistor in the lower leads and still no turn over.
verified all fuses are intact, at this point is it possible that my ecm could be the culprit?
the electronic service manual I have seems to not have a troubleshooting section but just consists of all the diagrams of all the vehicles systems and parts.
I would assume if the ecm is no good that other things would be acting up as well not just mimic of a vats security lockout.
verified all fuses are intact, at this point is it possible that my ecm could be the culprit?
the electronic service manual I have seems to not have a troubleshooting section but just consists of all the diagrams of all the vehicles systems and parts.
I would assume if the ecm is no good that other things would be acting up as well not just mimic of a vats security lockout.
With your resistor bypass use the same diagnostics I mentioned above and see what value the CCM sees.
With KEY ON not CRANKING a 'solid' SECURITY certainly hints a VATS event!!
Being a M6 if you had a failed Clutch Safety Switch you would have a similar experience. Maybe if the CCM gives you correct A/D counts you next jumper the CSS and see if you get CRANK!!
Pro
Joined: Apr 2018
Posts: 563
Likes: 201
From: Montgomery City, MO
The clutch safety switch has no bearing on the security lamp. If it doesn't go out when the ignition is turned to run it's a VATS issue. Also, I don't think you'll get a VATS DTC while VATS is active (meaning your passkey wasn't validated during key-on).
Ryanhabs you should look for the procedure to troubleshoot the A/D counts like suggested. I think may be in a separate book in the FSM from the CCM schematics - I don't have mine in front of me but can post which book / section later.
If you've bypassed the passkey circuit with an appropriate resistor and still no luck it would seem to indicate a possible broken wire or connector between there and the CCM, or a faulty CCM.
Ryanhabs you should look for the procedure to troubleshoot the A/D counts like suggested. I think may be in a separate book in the FSM from the CCM schematics - I don't have mine in front of me but can post which book / section later.
If you've bypassed the passkey circuit with an appropriate resistor and still no luck it would seem to indicate a possible broken wire or connector between there and the CCM, or a faulty CCM.
Last edited by spfautsch; Oct 4, 2021 at 03:36 PM.