Vette won't start, ecm code 46

[hall117]

Help! My vette won't start and the ecm is putting out a code 46 which the vechile anit theft system (VATS) but I don't know where it's at or how to trouble shoot it? Is VATS a module or computer or relay and where can I find it.

 

[Rob]

Welcome to the Corvette Action Center.

If you intend on servicing your Corvette on your own, I strongly recommend that you pick up a 1991 Service Manual. You can pick one up from Helm, MidAmerica, Ecklers and other vendors. For a full list, check the <a href="http://www.corvetteactioncenter.com/portal/index.php?cat=29&t=sub_pages">Parts and Service Manuals</a> section in our Corvette Portal.

According to the service manual, Code 46 is the Vehicle Anti-Theft System (VATS).

From the service manual:

Test Description: Numbers below refer to circled numbers on the diagnostic chart.

1. If the engine cranks but doesn't start, it indicates that the portion of the CCM which generates the signal to the ECM is not operating or the 229 CKT is open or shorted to ground. If the CCM module is found to be OK, as determined from the Central Control Module (CCM) (Section 8D), the ECM may be at fault, but this is not a likely condition.
2. If the engine will not crank, it indicates that there is a VATS problem or an incorrect key or starting procedure is being used.
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1. 
   The VATS lock cylinder is located where you place the ignition key. At this point, if you're going to pursue the repair, again, I strongly urge you to pick up a service manual as there are diagrams and instructions in there for proper diagnosis and repair. However, given the lag time seen in ordering service manuals due to backorders at some vendors, you may want to consider having the vehicle towed to your nearest Chevrolet dealership and have them work on it. Hope this helps.

 

[Drewser]

VATS

Welcome Hall117,

I am a locksmith and work on VATS all the time. You basically have a little resistor on your key (the little pellet) that comes in contact with two little brass plates inside your ignition. There are two fine little wires that connect the key to the module. These wires are very prone to break and fatigue. I would start there, but the problem here is that you have to be good at pulling steering wheels which entails using wheel pullers and lockplate compressors, pulling your turn signals and possibly and airbag (if so equipped, I forget if the 91 has an airbag) just to get to the ignition and then you have to be VERY careful that you don't break the wires while inspecting them. I have a tool called a VATS decoder/interrogator that I can either plug into the keyhole or the module to diagnose exactly where your problem is. Any good locksmith will have one. I would give a 'smith a shot at the work before I trusted a dealer, unless you have a good dealer. They are gonna want to gig you for something no matter what your problem is (if they are anything like OUR local dealer).

Let me know if you need any more info. Key are my life man.