FixVault
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Mazda
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2003
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MPV ES
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Repair and Diagnosis
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Engine Performance
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Engine Controls - Self-Diagnostics
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Diagnostic Tests
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DTC P0121: Throttle Position Sensor Stuck Closed/Open
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Possible Causes
Possible Causes
MAF sensor malfunction.
PCM malfunction.
TP sensor malfunction.
Voltage drops in constant voltage (Vref) supply circuit or ground circuit.