Suzuki Baleno Manual page 1281

DTC P0120 THROTTLE POSITION CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
Throttle
position
sensor
DTC DETECTING CONDITION
D Signal voltage high
or
D Signal voltage low
NOTE:
D When DTC P0105, P0110, P0115, P0120 and P0135 are indicated together, it is possible that "G/R" or "Or"
circuit is open.
D When this DTC and DTC P0105 are indicated together, it is possible that "P" circuit is open.
D When this DTC and P1700 are stored together, also clear DTC stored in TCM after completion of repair.
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and keep it at idle for 1 min.
2) Select "DTC" mode on scan tool and check DTC.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (G13/G16 ENGINE WITH WU TWC) 6-1-51
To other sensors
To other sensors
D "G/R" or "Or" circuit open
D "Gr" circuit open or shorted to ground
D "P" circuit open or shorted to power or ground
D TP sensor malfunction
D ECM (PCM) malfunction
ECM
(PCM)
POSSIBLE CAUSE