Asked by Apr 09, 2010 at 10:33 AM about the 2000 GMC Sierra 1500 SLT 4WD Extended Cab SB

Question type: Maintenance & Repair

my truck has 5 error codes P0122 throttle position sensor low input  the book says should be @ 5volts but i checked it and its @4.9 is that still too low? P0420,P0430 catalyst system efficiency below threshold left & right bank what dose that mean ? P1122 throttle position circuit intermittent low voltage . what does that mean ? checked TPS operation like the manual says 0.6@ closed position to 4.5 @full open position i got 0.6 to 4.4 does the .1 volt make a differance ? last one B0090 my book does not have this code .whats this code for . thanks for all your help.

1 Answer


.6 closed and 4.4 open are good numbers....a sensor should never been at 0 or 5 v. this would incicate either an open or a short. possible intermittent throttle position sensor (worn potentiometer contacts).....0420 is a cat code...could be related to throttle problem, as it might be causing it to run rich or lean...this could starve/flood the cat...fix the throttle problem clear codes and drive to see if other codes reset. also look at fuel trim readings while running/driving (need a scanner)...they should be at least under 10%...the closer to 0% the better..b0090 is an airbag code...unless the code is current or the airbag light stays on I wouldnt worry about it too much

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