P0121

Tests 1 - 3:

Tests 4 - 9:

Test 10:

SYMPTOM
P0121 - TPS VOLTAGE DOES NOT AGREE WITH MAP

WHEN MONITORED
With the engine running and no MAP sensor or TP sensor trouble codes.

SET CONDITION
PCM performs 2 separate tests on TPS. High voltage test when engine speed very low and manifold vacuum very high indicates throttle plate nearly closed. Low voltage test when engine speed > 25 mph and manifold vacuum low indicates the throttle plate is open, TPS signal high.

POSSIBLE CAUSES
- MAP sensor trouble code present
- TPS 5 volt supply circuit open
- TPS connectors & terminals observable defect
- TPS harness or connectors intermittent defect
- TPS voltage change not smooth
- TPS voltage above 1.0 volt
- TPS voltage above 3.5 volts