Suzuki Boulevard M50 User Manual

FI SYSTEM 5-59
“C29” (P1654-H/L) STP SENSOR CIRCUIT MALFUNCTION
INSPECTION
Step 1 (When indicating C29:)
1) Remove the fuel tank. (6-3)
2) Turn the ignition switch OFF.
3) Check the STP sensor coupler for loose or poor contacts.
If OK, then measure the STP sensor input voltage.
4) Disconnect the STP sensor coupler.
5) Turn the ignition switch ON.
6) Measure the voltage at the Red wire A and ground.
7) Also, measure the voltage at the Red wire A and B/Br wire B .
 STP sensor input voltage: 4.5 – 5.5 V
(+ Red – - Ground)
(+ Red – - B/Br)
 09900-25008: Multi-circuit tester set
 Tester knob indication: Voltage ()
Is the voltage OK?
DETECTED CONDITION POSSIBLE CAUSE
C29 Signal voltage is not within the following
range.
Difference between actual throttle open-
ing and opening calculated by ECM is
larger than specified value.
0.1 V Sensor voltage < 4.8 V
• STP sensor maladjusted
• STP sensor circuit open or short
• STP sensor malfunction
• ECM malfunction
P1654
H
Sensor voltage is higher than specified
value.
• STP sensor circuit shorted to VCC or ground cir-
cuit open
• STP sensor circuit open or shorted to ground or
VCC circuit open
L
Sensor voltage is lower than specified
value.
YES Go to Step 2.
NO
• Loose or poor contacts on the ECM coupler
(terminal 6 or D)
• Open or short circuit in the Red wire or B/Br
wire
ECM
E2
VCC
Y/W
R
STP
STP sensor
B/Br
Y
B
BI
1
1
V
SAMPLE

Suzuki Boulevard M50 Specifications

General

Compression Ratio	9.4:1
Fuel System	Fuel injection
Ignition	Electronic ignition (transistorized)
Transmission	5-speed constant mesh
Final Drive	Shaft drive
Front Suspension	Inverted telescopic, coil spring, oil damped
Front Tire	130/90-16M/C 67H, tubeless
Rear Tire	170/80-15M/C 77H, tubeless
Ground Clearance	140 mm (5.5 in)
Seat Height	700 mm (27.6 in)
Engine Type	4-stroke, liquid-cooled, V-twin
Bore x Stroke	83.0 mm x 74.4 mm
Rear Suspension	coil spring, oil damped
Front Brakes	Single hydraulic disc
Rear Brakes	Drum
Fuel Tank Capacity	15.5 L (4.1 US gal)
Wheelbase	1, 655 mm (65.2 in)