Suzuki WagonR+ RB310 Service Manual page 1845

6-1-82 GENERAL INFORMATION AND ENGINE DIAGNOSIS
DTC P0505 IDLE CONTROL SYSTEM MALFUNCTION
CIRCUIT DESCRIPTION
Main
fuse
"FI"
DTC DETECTING CONDITION
DTC will set when A, B or C condition is met.
A: Throttle opening change is small as compared with
electrically live time.
B: Throttle valve opening is not within its target range
with CTP switch ON.
C: Drive voltage exists though ECM (PCM) is not
outputting ISC drive command.
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Start cold engine.
4) Run it idle for 5 min.
5) Select "DTC" mode on scan tool and check DTC.
NOTE:
If engine speed changes up and down when engine speed is increased by opening throttle valve more
than half but not changing its opening, it is possible that closed throttle position switch is malfunction-
ing.
Main relay
Idle speed
control relay
Idle speed control actuator
To TP sensor
POSSIBLE CAUSE
D Maladjusted accelerator cable
D Poor movement of throttle valve
D Closed throttle position switch malfunction
D Idle speed control actuator malfunction
D Idle speed control relay malfunction
D "BLU/RED", "GRN/WHT", "GRN", "GRN/RED",
"WHT /GRN", "YEL/RED" or "BLK/YEL" circuit open
or short
D Throttle position sensor malfunction
D ECM (PCM) malfunction