1992 Buick Century Throttle Position Sensor

  • 6 CYL
  • FWD
  • 92,000 MILES

1992 Buick Century mileage: 92,000. I am having some trouble with my car. The problem occurred suddenly. The car starts and runs fine until about 15-20 minutes into the drive, then it just shuts off. After about a 5-10 min wait it fires right back up. Then after another short drive it shuts down again. Then it repeats the process. I found that when it shuts down I lose spark. The ignition coils check out o.K. In addition, I still have power to the ignition module so I changed the module, the problem still exists. I looked at the engine-wiring diagram and found two temperatures. Sensors 1 runs the fan (which seems to cycle o.K.) The other sends a signal to the temperature gauge and to the ECM. I am guessing the problem is temperature related, so I changed the temperature sensor and the problem still exists. I got three codes from the computer. 12, which I think, is a gm computer. Test code 21, I do not know and 42, I do not know. I am pulling out my hair on this one (what little I have left) are all these sensors really needed. Cars used to run fine without them. I hope you can help. Thank you.

Do you
have the same problem?
Thursday, October 14th, 2010 AT 7:03 PM

1 Reply


Your code 21 is TPS (Throttle Position Sensor), which means your signal voltage is high. Code 42 is EST (Electronic Spark Timing), which means your circuit is either open or grounded.

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Thursday, October 14th, 2010 AT 7:05 PM

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