29" (P1654-H/L) Stp Sensor Circuit Malfunction - Suzuki TU250X Service Manual

4-56 FI SYSTEM DIAGNOSIS

"29" (P1654-H/L) STP SENSOR CIRCUIT MALFUNCTION

DETECTED CONDITION
29 Signal voltage is not within the following
range.
Difference between actual throttle open-
ing and opening calculated by ECM is
larger than specified value.
0.35 V
P1654 Sensor voltage is higher than specified
H
value.
Sensor voltage is lower than specified
L
value.
Bl
Y
B
STP sensor

When using the multi circuit tester, do not strongly touch the terminal of the ECM coupler with
a needle-point probe to prevent the terminal damage or terminal bend.
INSPECTION
NOTE:
After repairing the trouble, clear the DTC using SDS tool.
(4-24)
Step 1 (When indicating 29:)
1) Turn the ignition switch OFF.
2) Lift up the fuel tank by removing the fuel tank mounting bolt.
(5-3)
3) Check the STP sensor coupler for loose or poor contacts.
If OK, then measure the STP sensor input voltage.
Sensor voltage < 4.9 V
POSSIBLE CAUSE
• STP sensor maladjusted
• STP sensor circuit open or short
• STP sensor malfunction
• ECM malfunction
• STP sensor circuit shorted to VCC or ground cir-
cuit open
• STP sensor circuit open or shorted to ground or
VCC circuit open
R
Bl/Y
B/Br
1
ECM
VCC
STPS
E2