Toyota 2GR-FE Manual page 327

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
Required Sensors/Components (Main)
Required Sensors/Components (Sub)
Frequency of Operation
Duration
MIL Operation
Sequence of Operation
TYPICAL ENABLING CONDITIONS
Monitor runs whenever following DTCs are not present
Either of following conditions A or B is met:
A. Engine switch
B. Electric throttle motor power
TP sensor malfunction (P0120, P0122, P0123, P0220, P0222, P0223,
P2135)
TYPICAL MALFUNCTION THRESHOLDS
Difference in voltage between VAT1 and VTA2
TP sensor 1 - [TP sensor 2 x 0.8 (corrected by learning value)]
FAIL-SAFE
When this DTC, as well as other DTCs relating to ETCS (Electronic Throttle Control System)
malfunctions, is set, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to
the throttle actuator off, and the throttle valve is returned to a 6° throttle angle by the return spring. The
ECM then adjusts the engine output by controlling the fuel injection (intermittent fuel-cut) and ignition
timing, in accordance with the accelerator pedal opening angle, to allow the vehicle to continue at a
minimal speed. If the accelerator pedal is depressed firmly and gently, the vehicle can be driven slowly.
Fail-safe mode continues until a pass condition is detected, and the engine switch is then turned off.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition
information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data
can be helpful in determining whether the vehicle was running or stopped, whether the engine was
warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of
a malfunction (See page ES-45).
1
CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0121)
2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
(a) Connect the intelligent tester to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the tester on.
P0121: TP sensor rationality
TP sensor
-
Continuous
Within 2 seconds
Immediate
None
P0120, P0122, P0123, P0220, P0222, P0223, P2135 (TP
sensor)
-
ON
ON
Not detected
Less than 0.8 V or more than 1.6 V
ES–171
ES