Suzuki WagonR+ RB310 Service Manual page 2413

6-54 ENGINE DIAGNOSIS
DTC P0121 THROTTLE POSITION CIRCUIT RANGE/PERFORMANCE
PROBLEM
CIRCUIT DESCRIPTION
Throttle
position
sensor
DTC DETECTING CONDITION
D After engine warmed up.
D While vehicle running at specified engine speed.
D No change in intake manifold pressure (constant throttle opening)
D Difference between actual throttle opening (detected from TP sensor)
and opening calculated by ECM (Obtained on the basis of engine
speed and intake manifold pressure) in larger than specified value.
: 2 driving cycle detection logic, continuous monitoring
DTC CONFIRMATION PROCEDURE
WARNING:
D When performing a road test, select a place where there is no traffic or possibility of a traffic accident
and be very careful during testing to avoid occurrence of an accident.
D Road test should be carried out with 2 persons, a driver and a tester, on a level road.
1) Turn ignition switch OFF. Clear DTC with ignition switch ON, check vehicle and environmental condition for:
– Indication of fuel level meter in combination meter: 1/4 or more
– Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
– Ambient temp.: –10_C, 14_F or higher
– Intake air temp.: 70_C, 158_F or lower
– Engine coolant temp.: 70 – 110_C, 158 – 230_F
2) Warm up engine to normal operating temperature.
3) Increase vehicle speed to 30 – 40 mph, 50 – 60 km/h in 3rd gear or "D" range and hold throttle valve at that
opening position for 1 min.
4) Stop vehicle.
5) Check DTC in "DTC" mode and pending DTC in "ON BOARD TEST" or "PENDING DTC" mode.
To other sensors
To other sensors
E21-10
E23-5
E21-22
POSSIBLE CAUSE
D TP sensor malfunction
D High resistance in the circuit
D ECM malfunction