Monitor Description

The ECM uses the TP sensor to monitor the throttle valve opening angle.

This sensor transmits two signals: VTA1 and VTA2. VTA1 is used to detect the throttle opening angle and VTA2 is used to detect malfunctions in VTA1. The ECM performs several checks to confirm the proper operation of the TP sensor and VTA1.

For each throttle opening angle, a specific voltage difference is expected between the outputs of VTA1 and VTA2. If the output voltage difference between the two signals deviates from the normal operating range, the ECM interprets this as a malfunction of the TP sensor. The ECM illuminates the MIL and sets the DTC.

If the malfunction is not repaired successfully, the DTC is set 2 seconds after the engine is next started. MONITOR STRATEGY

Related DTCs

P0121: TP sensor rationality

Required Sensors/Components (Main)

TP sensor

Required Sensors/Components (Related)


Frequency of Operation



Within 2 seconds

MIL Operation


Sequence of Operation



Monitor runs whenever following DTCs not present

P0120 - P0223, P2135 (TP sensor)

Either of following conditions A or B set


A. Ignition switch


B. Electric throttle motor power



Difference in voltage between VAT1 and VTA2

TP sensor 1 - [TP sensor 2 x 0.8 (corrected by learning value)]

Less than 0.S V, or more than 1.6 V

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