Car will not start after bypassing key with a four OHM resistor

SCOTT JENKINS2

MEMBER
2001 CHEVROLET LUMINA
FWD
AUTOMATIC
160,000 MILES

First I had the blinking security light so I bypassed the pass key with a four ohm resistor. Security stopped flashing, but still no start. Next I did the re-boot protocol where I try to start, leave in run position for ten minutes three times, but still no start. Any suggestions on next step?

4 Replies

HMAC300

MECHANIC
48,601 POSTS

Take the resistor out and try it if that does not work it will need to be scanned for codes by a mechanic to see what is wrong with system.

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Thursday, December 15th, 2016 AT 9:47 AM

STEVE W.

MECHANIC
13,014 POSTS

What did the resistance in the original key read? Four ohms does not match any of the passkey values. They start much higher. Wrong resistor will prevent it from starting.

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Thursday, December 15th, 2016 AT 10:02 AM

SCOTT JENKINS2

MEMBER
2 POSTS

It did clear the flashing security light so that should mean I got it right? Digital meter read 7.3 but analogread four ohms.

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Thursday, December 15th, 2016 AT 10:06 AM

STEVE W.

MECHANIC
13,014 POSTS

Neither of those are valid numbers for the system either. On 01 to 03 GMs there are 14 values from 523 ohms up to 11,800 ohms. You have to be within 3% of the correct number for it to work.

What was the reason you started using the resistors for? If it was a no start/security light with a known correct key it could be a problem anywhere from the contacts in the switch to the ECM.
If you have a low battery it can also cause problems because the system looks for a certain voltage drop across the key, low battery = wrong voltage.

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Thursday, December 15th, 2016 AT 4:43 PM