Is There a way I could measure the Resistance of a Ignition key on my 1989 corvette to order A spare key. they are asking for a Code 1-15.The dealership wants $100.00 That's Expensive.

B1353 Ignition Key-In Circuit Open GEM Go to Pinpoint Test B .
PINPOINT TEST B: THE KEY-IN-IGNITION CHIME DOES NOT OPERATE CORRECTLY
Do you know what the GEM - genaric electronic control is ?
You need a scan tool to check ignition switch position .Don't know if this would cause a no start . Have you check for ignition spark and fuel pressure ? Are there anyother problems with power door locks or windows or lighting ? Thing's the GEM controls ?
CONDITIONS DETAILS/RESULTS/ACTIONS B1 CHECK IGNITION STATES
NGS
Monitor the GEM PIDS IGN_KEY, IGN_A, IGN_S, and IGN_R while cycling the ignition switch through the OFF, ACC, RUN, START and key out positions.

• Do the PID values agree with the ignition switch states?

Yes GO to B2 .

No GO to B4 . B2 CHECK GEM INTERNAL TONE OPERATION Trigger the GEM Active Command CHIME ON and OFF.

• Does the chime operate correctly?

Yes GO to B3 .

No INSTALL a new GEM. For additional information, REFER to Section 419-10 . REPEAT the self test. CLEAR the DTCs. B3 CHECK GEM INPUT FROM DOOR AJAR CIRCUIT Monitor the GEM PID D_DR_SW, while opening and closing the driver door.

• Do the GEM PID D_DR_SW values indicate CLOSED and AJAR correctly?

Yes INSTALL a new GEM. For additional information, REFER to Section 419-10 . REPEAT the self test. CLEAR the DTCs.

No GO to Pinpoint Test D . B4 CHECK GEM INPUT VOLTAGE FROM IGNITION SWITCH AT CJB FUSE 28 (15A)
CJB Fuse 28 (15A)
Measure the voltage between CJB Fuse 28 (15A), Pin 1, harness side and ground while cycling the ignition switch through all positions.

• Is the voltage greater than 10 volts in the RUN and START positions only?

Yes GO to B5 .

No REPAIR the CJB. REPEAT the self test. CLEAR the DTCs. B5 CHECK GEM INPUT VOLTAGE FROM IGNITION SWITCH AT CJB FUSE 32 (15A)
CJB Fuse 32 (15A)
Measure the voltage between CJB Fuse 32 (15A), Pin 1, harness side and ground while cycling the ignition switch through all positions.

• Is the voltage greater than 10 volts in the RUN and ACC positions only?

Yes GO to B6 .

No REPAIR the CJB. REPEAT the self test. CLEAR the DTCs. B6 CHECK GEM VOLTAGE INPUT CIRCUITS FOR OPEN - IGNITION SWITCH CIRCUIT 911 (WH/LG)
CJB Fuse 28 (15A)

GEM C352
Insert ignition key. Measure the resistance between GEM C352 Pin 8, Circuit 911 (WH/LG), harness side and CJB Fuse 28 (15A) Pin 2, Circuit 911 (WH/LG), harness side.

• Is the resistance less than 5 ohms?

Yes GO to B7 .

No REPAIR Circuit 911 (WH/LG). REPEAT the self test. CLEAR the DTCs. B7 CHECK GEM VOLTAGE INPUT CIRCUITS FOR OPEN - IGNITION SWITCH CIRCUIT 1002 (BK/PK) Measure the resistance between GEM C352 Pin 22, Circuit 1002 (BK/PK), harness side and CJB Fuse 32 (15A), Pin 2, Circuit 1002 (BK/PK), harness side.

• Is the resistance less than 5 ohms?

Yes GO to B8 .

No REPAIR Circuit 1002 (BK/PK). REPEAT the self test. CLEAR the DTCs. B8 CHECK GEM INPUT CIRCUIT FOR OPEN - KEY-IN-IGNITION SWITCH CIRCUIT 158 (BK/PK) Measure the resistance between GEM C352 Pin 9, Circuit 158 (BK/PK), harness side and ground.

• Is the resistance less than 5 ohms?

Yes GO to B9 .

No REPAIR Circuit 158 (BK/PK) and key-in-ignition switch for failure. For additional information, REFER to Switch-Key-In-Ignition Warning . REPEAT the self test. CLEAR the DTCs. B9 CHECK GEM VOLTAGE INPUT CIRCUITS FOR SHORT TO POWER - IGNITION SWITCH CIRCUITS 911 (WH/LG), AND 1002 (BK/PK)
CJB Fuse 28 (15A)

CJB Fuse 32 (15A)

GEM C352
Remove ignition key. Measure the voltage between GEM C352 Pin 8, Circuit 911 (WH/LG), harness side and ground, and between GEM C352 Pin 22, Circuit 1002 (BK/PK), harness side and ground.

• Are voltages greater than 10 volts?

Yes REPAIR the circuit in question. REPEAT the self test. CLEAR the DTCs.

No GO to B10 . B10 CHECK GEM INPUT CIRCUIT FOR SHORT TO GROUND -- KEY-IN-IGNITION SWITCH CIRCUIT 158 (BK/PK)
GEM C352
Remove ignition key. Measure the resistance between GEM C352 Pin 9, Circuit 158 (BK/PK), harness side and ground.

• Is the resistance greater than 10,000 ohms?

Yes INSTALL a new GEM. For additional information, REFER to Section 419-10 . REPEAT the self test. CLEAR the DTCs.

No REPAIR Circuit 158 (BK/PK). REPEAT the self test. CLEAR the

Without knowing the resistance of the pellet on the key the anti -theft system will not allow it to start .

PASS-Key® II is a registered trademark of the Delco Electronics Corporation.
When a key is inserted in the ignition, the contacts located in the ignition cylinder contact a resistor pellet located in the key. The instrument cluster (IPC) measures the resistance of the key pellet. The IPC then compares this value to a value stored in the IPC's memory. The IPC then performs one of the following functions: A new key shouldn't cost that much , a whole new ignition lock cylinder with a new key can be bought for $36.00 . on line .

You can take a resistance measurement of the ignition key/chip with an ohm meter. When you get the resistance measurement, you can buy a resistor of the same resistance/close resistance ( a bag of resistors cost 5 bucks ) at the source/radio shack and cut the wire from the ignition switch and install the resistor. The passlock system will be fooled into thinking the key is being used. Takes a bit of time but works

Passlock you mean? That system is not resettable persay. It works when it decides the correct conditions are met. Those conditions come down to a chip in the ignition key has a certain ohms reading, and the BCM is programmed to only start when it sees 2 wite wires feed put of the BCM, up to the key, through the chip (1 wire in, 1 wire out) and back to the security module. There are like 12 different resistance key values and the key will never change but the lock cylinder tends to wear out and break its wires.

If this has happened...youd need a new lock cylinder.
If you want a cheaper fix...there isnt an easy one, however at the base of the steering column where the wires come down from the ignition and turn signal, one bulky wire is wrapped in bright orange cloth insulation and heads off alone upwards in the dash, That orange wire wrap contains the 2 tiny white wires that measure your key resistance and tell the BCM its OK to start the car, You COULD (Not saying you should!) take your ignition key to any radio shack...ask them to measure the resistance if the pellet in the key. one side of the key to the other,. Then have them sell you a resistor that totals the same resistance (plus or minus 10 or 20 is usually fine) and then install that new matched resistor between the 2 white wires and the car should start right back up because it will think the key is inserted and the wires are good again,.Ive even seen a really hungry tech take the spare key, cut the 2 white wires under the dash...TAPE one to each side of the key pellet, then wrap and ziptie the wires with backup key permanently connected to the 2 white wires back together and leave it like that.
But thats strictly Gilligans island level, you are better off fixing it properly. But the above will work in a pinch,

Did you use the correct ignition switch lock cylinder for the key code you have? If not the security system is activated. You must measure the resistance of the wire in the shaft of the old key and then order it based on that which translates into a code number.
Vats/Passkey Key Codes & Resistances
(Ordered in KEY BLANK numbers from 1 to 15, Resistances in Ohms)

does your key have a black pellet at the base? if so try a new key! must have the pellet in it! if problem is still there after that! the ingition cylinder needs to be replace!

Any hardware store can duplicate keys, lock smith in your area, big box store (the home improvement kind).

Should be pretty simple ... in my area it costs about $2.00 to duplicate a key.

Well first off your vehicle uses the obd1 system not obd2.

Code 43 indicates a problem in the spark control circuit. The computer sets this code when the computer feels that it has lost control of the ignition system. Turn the ignition switch OFF and Unplug the ignition coil. Measure the primary resistance. It should be 0.095 - 1.20 ohms. Measure the secondary resistance. It should be 11,300 - 15,300 ohms. If these are not correct, replace the coil. A Black/Gray wire runs from the computer to the ignition coil. With the ignition switch OFF, unplug the coil and check the continuity of this wire from the coil connector to the computer. The wire should have a low resistance between the ends, and a high resistance to ground. If it measures otherwise, repair the wire. With the key on, measure the voltage from the dark Green/Orange wire to ground. It should be +12 volts. If it is not, turn the key off, remove the ASD relay, and measure continuity from the ignition coil connector to pin 87 in the ASD relay socket. If this is not a low resistance, repair the wire. TERMINAL LEGEND NUMBER IDENTIFICATION
30 Common Feed 85 Coil Ground 86 Coil Battery 87 Normally Open 87A Normally Closed

access the lamp from under the car--may have to remove the spare tire to access. be carefull the sockets break easy

your car was build with an anti-theft devise from GM, inside the ignition key is a micro-chip, when you insert the key in the ignition cylinder, the sensor inside the cylinder will measure the resistance of that micro-chip inside the key, if there is a match the engine will start, if no match the computer will think someone is trying to steal your car & shut it off.
try using another ignition key (spare key) if this doesn't work most likely the tiny wire inside the ignition cylinder is broken therefore the ignition cylinder will need to be replaced.