Honda Crf250l Service Manual

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PGM-FI SYSTEMMIL 8 BLINKS (TP SENSOR) 
Probable cause
 • Open circuit in Yellow/red wire between the sensorunit and ECM
 • Open or short circuit in Yellow wire between the sensor unit and ECM
 • Open circuit in Green/white wire between the sensor
unit and ECM
 • Faulty sensor unit
 • Faulty ECM
1. Sensor Unit Power Line Inspection
Check the sensor unit power line inspection (page
4-8).
Is the sensor unit power line normal?
YES – GO TO STEP 2.
NO – Replace or repair the abnormal circuit.
2. TP Sensor Output Line Short Circuit Inspection Turn the ignition switch OFF.
Disconnect the ECM 33P (Black) connector and
sensor unit 5P connector [1] (page 4-44).
Check for continuity between the sensor unit 5P
connector of the wire side and ground.
Is there continuity?
YES – Short circuit in Yellow wire
NO – GO TO STEP 3.
Y/R
G/W
5 V
ECM
SENSOR UNIT 
(TP SENSOR)
Y
Connection: Yellow – Ground Y
[1] 
						

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PGM-FI SYSTEM
3. TP Sensor Output Line Open Circuit InspectionCheck for continuity between the ECM 33P (Black)
connector [1] and sensor unit 5P connector [2] of
the wire side.
Is there continuity?
YES – GO TO STEP 4.
NO – Open circuit in Yellow wire
4. TP Sensor Resistance Inspection Connect the sensor unit 5P connector.
Check that the resistance  varies in accordance with
the throttle operation at the ECM 33P (Black)
connector of the wire side.
Is the resistance normal?
YES – Replace the ECM with a known good one,
and recheck.
NO – Faulty sensor unit (TP sensor)
MIL 9 BLINKS (IAT SENSOR)
Probable cause
 • Open or short circuit in Gray/blue wire between the
sensor unit and ECM
 • Open circuit in Green/white wire between the sensor unit and ECM
 • Faulty sensor unit
 • Faulty ECM Connection: Yellow – Yellow
TOOL:
Test probe
07ZAJ-RDJA110
Y
[1][2]Y
Connection: Yellow – Green/white
Fully closed-Fully open position:
Resistance increases
Fully open-Fully closed position:
Resistance decreases
[1] G/W
Y
Gr/Bu
G/W
5 V
ECM
SENSOR UNIT 
(IAT SENSOR) 
						

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PGM-FI SYSTEM
1. Sensor Unit Power Line InspectionCheck the sensor unit power line inspection (page
4-8).
Is the sensor unit power line normal?
YES – GO TO STEP 2.
NO – Replace or repair the abnormal circuit.
2. IAT Sensor Output Voltage Inspection Turn the ignition switch OFF.
Connect the ECM 33P (Black) connector.
Disconnect the sensor unit 5P connector [1] (page
4-44).
Turn the ignition switch ON and engine stop switch
.
Measure the voltage at the sensor unit 5P connector
of the wire side.
Is the voltage within 4.75 – 5.25 V?
YES – GO TO STEP 5.
NO – GO TO STEP 3.
3. IAT Sensor Output Line Short Circuit Inspection Turn the ignition switch OFF.
Disconnect the ECM 33P (Black) connector.
Check for continuity between the sensor unit 5P
connector [1] of the wire side and ground.
Is there continuity?
YES – Short circuit in Gray/blue wire
NO – GO TO STEP 4.
4. IAT Sensor Output Line Open Circuit Inspection Check for continuity between the ECM 33P (Black)
connector [1] and sensor unit 5P connector [2] of
the wire side.
Is there continuity?
YES – Replace the ECM with a known good one
and recheck.
NO – Open circuit in Gray/blue wire
Connection: Gray/blue (+) – Green/white (–)
Standard: 4.75 – 5.25 V
Gr/Bu
G/W
[1]
Connection: Gray/blue – GroundGr/Bu
[1]
Connection: Gray/blue – Gray/blue 
TOOL:
Test probe 07ZAJ-RDJA110
Gr/Bu
[1][2] Gr/Bu 
						

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PGM-FI SYSTEM
5. IAT Sensor Resistance InspectionTurn the ignition switch OFF.
Connect the sensor unit 5P connector.
Disconnect the ECM 33P (Black) connector [1].
Measure the resistance at the ECM 33P (Black)
connector of the wire side.
Is the resistance within 1.13 – 1.88 k Ω (20°C/
68°F)?
YES – Replace the ECM with a known good one,
and recheck.
NO – Faulty sensor unit (IAT sensor)
MIL 11 BLINKS (VS SENSOR)
Before starting the inspection, check for loose or poor contact on the VS sensor 3P (Blue) connector and
recheck the MIL blinking.
Probable cause
 • Open or short circuit in Pink or White/red wire
between the VS sensor and ECM
 • Faulty VS sensor
 • Faulty ECM
1. Speedometer Inspection
Inspect the speedometer (page 20-8).
Is the speedometer normal?
YES – GO TO STEP 2.
NO – Replace or repair the abnormal circuit.
Connection: Gray/blue – Green/white 
Standard: 1.13 – 1.88 k
Ω (20°C/68°F)
Gr/Bu
G/W
[1]
G/Bl
Bl/R
ECM
VS SENSOR
To SPEEDOMETER
W/RW/R
G
Bl
P 
						

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PGM-FI SYSTEM
2. VS Sensor Signal Line InspectionTurn the ignition switch OFF.
Disconnect the ECM 33P (Black) connector [1].
Turn the ignition switch ON and engine stop switch
.
Measure the voltage at the ECM 33P (Black)
connector of the wire side.
Slowly turn the rear wheel by hand.
There should be 0 V to 5 V pulse voltage.
Is there 0 – 5 V pulse voltage?
YES – Replace the ECM with a known good one
and recheck.
NO – Open or short circuit in White/red wire.
MIL 12 BLINKS (INJECTOR)
Before starting the inspection, check for loose or poor contact on the injector 2P (Gray) connector and recheck
the MIL blinking.
Probable cause
 • Open circuit in Black/blue wire between the engine
stop switch and injector
 • Open or short circuit in Pink/white wire between the injector and ECM
 • Faulty injector
 • Faulty ECM Connection: White/red (+) – Ground (–)
TOOL:
Test probe
07ZAJ-RDJA110
W/R
[1]
Bl/Bu
ECM
INJECTOR
From ENGINE 
STOP SWITCH
P/W 
						

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PGM-FI SYSTEM
1. Injector Input Voltage InspectionTurn the ignition switch OFF.
Disconnect the injector 2P (Gray) connector [1]
(page 7-14).
Turn the ignition switch ON and engine stop switch
.
Measure the voltage between the injector 2P (Gray)
connector of the wire side and ground.
Does the standard voltage exist?
YES – GO TO STEP 2.
NO – Open circuit in Black/blue wire
2. Injector Signal Line Short Circuit Inspection Turn the ignition switch OFF.
Disconnect the ECM 33P (Black) connector.
Check for continuity between the injector 2P (Gray)
connector [1] of the wire side and ground.
Is there continuity?
YES – Short circuit in Pink/white wire
NO – GO TO STEP 3.
3. Injector Resistance Inspection Measure the resistance between the injector side
connector [1] terminals.
Is the resistance within 11 – 13  Ω (20°C/68°F)?
YES – GO TO STEP 4.
NO – Faulty injector
4. Injector Signal Line Open Circuit Inspection Check for continuity between the ECM 33P (Black)
connector [1] and injector 2P (Gray) connector [2] of
the wire side.
Is there continuity?
YES – Replace the ECM with a known good one,
and recheck.
NO – Open circuit in Pink/white wire
Connection: Black/blue (+) – Ground (–)
Standard: Battery voltage
Bl/Bu
[1]
Connection: Pink/white – GroundP/W
[1]
Standard: 11 – 13 
Ω (20°C/68°F)
[1]
Connection: Pink/white – Pink/white
TOOL:
Test probe 07ZAJ-RDJA110
P/W
[1][2]
P/W 
						

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PGM-FI SYSTEMMIL 21 BLINKS (O
2 SENSOR)
Before starting the inspection, check for loose or poor contact on the O2 sensor 1P (Black) connector or O2sensor cap and recheck the MIL blinking.
Probable cause
 • Open or short circuit in Black/white or Black wirebetween the O
2 sensor and ECM
 • Faulty O2 sensor
 • Faulty ECM
1. O
2 Sensor System Inspection
Start the engine and warm up the engine up to
coolant temperature is 80°C/176°F.
Test-ride the motorcycl e and recheck the MIL
blinking.
Does the MIL blink 21 times?
YES – GO TO STEP 2.
NO – Intermittent failure
2. O
2 Sensor Short Circuit Inspection
Turn the ignition switch OFF.
Disconnect the ECM 33P (Black) connector (page
4-50).
Disconnect the O
2 sensor cap [1] (page 4-47).
Check for continuity between the O
2 sensor cap
terminal [2] and ground.
Is there continuity?
YES – Short circuit in Black or Black/white wire
NO – GO TO STEP 3.
Bl/W
ECM
O2 SENSOR
Bl
Connection: O2 sensor cap terminal – Ground 
[1]
[2] 
						

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PGM-FI SYSTEM
3. O2 Sensor Open Circuit Inspection
Check for continuity between the ECM 33P (Black)
connector [1] and O
2 sensor cap terminal [2] of the
wire side.
Is there continuity?
YES – GO TO STEP 4.
NO – Open circuit in Black or Black/white wire
4. O
2 Sensor Inspection
Replace the O
2 sensor with a known good one
(page 4-47).
Connect the ECM 33P (Black) connector.
Start the engine and warm up the engine up to
coolant temperature is 80°C/176°F.
Test-ride the motorcycle and recheck the MIL
blinking.
Does the MIL blink 21 times?
YES – Replace the ECM with a known good one,
and recheck.
NO – Faulty original O
2 sensor
MIL 29 BLINKS (IACV)
Before starting the inspection, check for loose or p oor contact on the IACV 4P (Black) connector and recheck
the MIL blinking.
Probable cause
 • Open or short circuit in wires (Blue/white, Blue/black,
Brown/white, Brown/black) between the IACV and
ECM
 • Faulty IACV
 • Faulty ECM Connection: O
2 sensor cap terminal – Black/
white
TOOL:
Test probe 07ZAJ-RDJA110[1]
[2]
Bl/W
Bu/W
ECM
IACV
Bu/Bl
Br/W
Br/Bl 
						

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PGM-FI SYSTEM
1. IACV Resistance InspectionTurn the ignition switch OFF.
Disconnect the IACV 4P (Black) connector [1] (page
7-15).
Measure the resistance at the IACV side connector.
Is the resistance within 110 – 150  Ω (25°C/77°F)?
YES – GO TO STEP 2.
NO – Faulty IACV
2. IACV Short Circuit Inspection Disconnect the ECM 33P (Black) connector (page
4-50).
Check for continuity between the IACV 4P (Black)
connector [1] of the wire side and ground.
Is there continuity?
YES –  • Short circuit in Blue/white or Brown/
white wire
 • Short circuit in Brown/black or Blue/
black wire
NO – GO TO STEP 3.
3. IACV Open Circuit Inspection Check for continuity between the ECM 33P (Black)
connector [1] and IACV 4P (Black) connector [2] of
the wire side.
Is there continuity?
YES – Replace the ECM with a known good one,
and recheck.
NO –  • Open circuit in Blue/white or Brown/
white wire
 • Open circuit in Brown/black or Blue/ black wire
Connection: A (Blue/black) – D (Blue/white)
B (Brown/black) – C (Brown/white)
Standard: 110 – 150  Ω (25°C/77°F)
A
D
C
B
[1]
Connection: Blue/white – Ground
Brown/white – Ground
Brown/black – Ground
Blue/black – Ground
Bu/Bl
Bu/W Br/W Br/Bl
[1]
Connection: Brown/white – Brown/white
Blue/white – Blue/white
Brown/black – Brown/black
Blue/black – Blue/black
TOOL:
Test probe 07ZAJ-RDJA110
Bu/Bl
Bu/W Br/W
Br/Bl
[2]
Bu/Bl
Bu/W
Br/WBr/Bl
[1] 
						

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PGM-FI SYSTEM
MIL 54 BLINKS (BANK ANGLE 
SENSOR)
Before starting the inspection, check for loose or poor contact on the bank angle  sensor 2P connector and
recheck the MIL blinking.
Probable cause
 • Open circuit in Black/blue wire between the engine
stop switch and bank angle sensor
 • Open or short circuit in Red/blue wire between the bank angle sensor and ECM
 • Faulty bank angle sensor
 • Faulty ECM
1. Bank Angle Sensor Input Voltage Inspection
Turn the ignition switch OFF.
Disconnect the bank angle sensor 2P connector [1]
(page 4-48).
Turn the ignition switch ON and engine stop switch
.
Measure the voltage between the bank angle
sensor 2P connector of the wire side and ground.
Is there battery voltage?
YES – GO TO STEP 2.
NO – Open circuit in Black/blue wire
From ENGINE 
STOP SWITCH
ECM
BANK ANGLE SENSOR
Bl/Bu
R/Bu
Connection: Black/blue (+) – Ground (–)
Standard: Battery voltage
[1]
Bl/Bu