Honda Crf250l Service Manual

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PGM-FI SYSTEM
PGM-FI SYSTEMSERVICE INFORMATION
GENERAL
 • A faulty PGM-FI system is often related to poorly connected or corroded connectors. Check those connections before
proceeding.
 • When disassembling the PGM-FI syst em parts, note the location of the O-rings. Replace them wi th new ones upon reassembly.
 • Use a digital tester for PGM-FI system inspection.
 • The following color codes are used throughout this section.
PGM-FI SYSTEM LOCATION
Bu = Blue G = Green Lb = Light Blue O = Orange R = Red Y = Yellow
Bl = Black Gr = GrayLg = Light Green P = Pink W = White Br = Brown
IGNITION SWITCH
INJECTOR
BANK ANGLE SENSOR
DLC
O2 SENSOR
SENSOR UNIT:
– MAP SENSOR
– IAT SENSOR
– TP SENSOR
CKP SENSOR
IACV
ECT SENSOR
FUEL PUMP
ECM
ENGINE STOP SWITCH
VS SENSOR 
						

							4-3
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PGM-FI SYSTEM
PGM-FI SYSTEM DIAGRAM
(1)(8) (12)
(9) (7)
30
K-LINE
IACV1A
IACV2A
(21)
(29)
IAT SENSOR
ECT SENSOR
O
2 SENSOR
MAP SENSOR
SENSOR UNIT
CKP SENSOR
27 PB 25 SSTAND
UP
DOWN 29 NLSW
12 PCP
23 PCM8
FLR
TW-IND
5THL
14 TA
24 TW
3 6 VCC 4SG 1
IGP
16
INJ 19
FA N C
9 PG1 10 PG2 2 LG O2
TP SENSOR FUEL PUMP UNIT
FUEL
PUMP
RELAY
SPEEDOMETER
VS SENSOR MIL
HIGH COOLANT
TEMPERATURE INDICATOR
FA N
CONTRO
LRELAY
INJECTOR
IGNITION COIL
SCS CONNECTOR
IACV
26 BA
11
IGPLS
28
EX-AI
PAIR CONTROL 
S O L E N O I D  VA LV E SPARK PLUG
18
22
FI-IND
17
VSP
ALTERNATOR
IGNITION SWITCH
ENGINE STOP SWITCH
STARTER SWITCH
STARTER
RELAY
SWITCH
NEUTRAL
SWITCH SIDESTAND SWITCH CLUTCH
SWITCH
REGULATOR/
RECTIFIER
BATTERY
MAIN
FUSE
(30 A) METER, TAIL 
FUSE (10 A)
FI, IGN FUSE (10 A)
FAN FUSE (10 A)
15
21
32
20
31
SCS
IACV1B
IACV2B
1
12
23 22
11
33
BANK ANGLE
SENSOR
(54)
DLC
(   )  : MIL number
: Engine does not start
  when detecting MIL :Short terminals for
  reading MIL
ECM 33P  (
BLACK )
 CONNECTOR
(ECM side of the male terminals)
R : Red G : Green Y : Yellow Bl : Black
Bu : Blue Br : Brown
Lg : Light green O : Orange
Gr : Gray W : White
(11)
P : Pink
ECM
DIODE STARTER 
MOTOR
Bu
Bu/W
Br/WBr/Bl
Bu/Bl Y
G/R
O/G
G/Bu
W/Bu
Bl/Bu
Br
P/W
Bl/G
W/R
G
Bl/Bu
G G
G/Bl Bl/Bu Bl/Bu
Bl/Bu
Lg/Bl Bu/Y
G/OG/R
G/R
G/O
G/W
G G/R
Lg/R
W/Y
Gr/Bu Y/BuG/W Y/R
Bl/W
R/Bu
Bl/Bu Bl
G Bl/Bu
Bl/Bu
Y R/W Bl/R
BlBl/W
Br
Br/R
Bl/W Y/R
G Bl/G
Bl/Bu
G
R/W
R/W
R/W
G/R Y/R
R/W
Bl/Bu
YY Y
Bl Bl/W Bl/WBu G
G/Bl
Bl/R
W/R
G
Bl
P
Bl Bl 
						

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PGM-FI SYSTEM
PGM-FI TROUBLESHOOTING INFORMATION
GENERAL TROUBLESHOOTING
Intermittent Failure
The term intermittent failure means a system may have had a failure, but it checks OK now. If the MIL does not come on, check
for poor contact or loose pins at all connectors related to the  circuit that of the troubleshooting. If the MIL was on, but then went out,
the original problem may be intermittent.
Opens and Shorts
Opens and Shorts are common electrical  terms. An open is a break in a wire or at a connection. A short is an accidental
connection of a wire to ground or to another wire. In simple elec tronics, this usually means something will not work at all. With
ECMs this can something mean something work, but not the way it’s supposed to.
If the MIL has come on
Refer to DTC READOUT (page 4-5).
If the MIL did not stay on
If the MIL did not stay on, but th ere is a driveability problem, do the SYMPTOM TROUBLESHOOTING (page 4-6).
SYSTEM DESCRIPTION
SELF-DIAGNOSIS SYSTEM
The PGM-FI system is equipped with the self-d iagnostic system. When any abnormality occurs in the system, the ECM turns on the
MIL and stores a DTC in its erasable memory.
FAIL-SAFE FUNCTION
The PGM-FI system is provided with a fail-safe function to secu re a minimum running capability even when there is trouble in th e
system. When any abnormality is detected by  the self-diagnosis function, running capability is maintained by pre-programed valu e
in the simulated program map. When any abno rmality is detected in the injector, the fail-safe function stops the engine to protect it
from damage.
MIL Blink Pattern 
 • DTC can be read from the ECM memory by the MIL blink pattern.
 • The MIL will blink the current DTC, in  case the ECM detects the problem at present, when the ignition switch ON and engine
stop switch   or idling. T he MIL will stay ON when the engine speed is over 2,100 min
-1 (rpm).
 • The MIL has two types of blinks, a long blink and short blink.  The long blinking lasts for 1.3 seconds, the short blinking lasts for
0.3 seconds. One long blink is the equivalent of ten short blinks. For example, when two long blinks are followed by five short
blinks, the MIL is 25 (two long blinks  = 20 blinks, plus five short blinks).
 • When the ECM stores more than  one DTC, the MIL will indicate them by blinking  in the order from the lowest number to highest
number.
MIL Check
When the ignition switch is turned ON and engine stop switch    the MIL will stay on for a few seconds, then go off. If the MIL does
not come on, troubleshoot the MIL circuit (page 4-43).
CURRENT DTC/STORED DTC
The DTC is indicated in two ways according to the failure status.
 • In case the ECM detects the problem at  present, the MIL will come on and the MIL will start to blink as its DTC when the
sidestand is lowered. It is possible to rea dout the MIL blink pattern as the current DTC.
 • In case the ECM does not detect any problem at present but ha s a problem stored in its memory, the MIL will not light and blink.
If it is necessary to retrieve the past problem, readout the  stored DTC by following the DTC readout procedure (page 4-5). 
						

							4-5
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PGM-FI SYSTEM
HDS POCKET TESTER INFORMATION
 • The HDS pocket tester can readout the DTC,  freeze data, current data and other ECM condition.
How to connect the HDS pocket tester
Turn the ignition switch OFF.
Remove the dummy connector [1] from the DLC [2].
Connect the HDS pocket tester to the DLC.
Turn the ignition switch ON and engine stop switch   check the DTC and
freeze data.
Freeze data indicates the engine conditions when the first malfunction was
detected.
ECM reset
The HDS pocket tester can reset the ECM data including the DTC, freeze
data and some learning memory.
After the ECM reset, perform the TP sensor reset procedure (page 4-45).
DTC READOUT
Start the engine and check the MIL.
When the ignition switch is turned ON a nd engine stop switch  , the MIL will st ay on for a few seconds, then go off.
If the MIL stays on or blinks, read the DTC, freeze  data and follow the troubleshooting index (page 4-7).
To read the DTC with the MIL blinki ng, refer to the following procedure.
Reading DTC with the MIL
Turn the ignition switch OFF.
Remove the dummy connector from the DLC [1].
Short the DLC terminals using the special tool.
Turn the ignition switch ON and engine stop switch  , read, note the MIL
blinks and refer to the DTC index (page 4-7).
If the ECM has any DTC in its memory, the MIL will start blinking.
ERASING DTC
1. Turn the ignition switch OFF.
2. Remove the dummy connector from the DLC [1]. Short the DLC terminals using the special tool.
3. Turn the ignition switch ON and engine stop switch  .
4. Remove the special tool from the DLC.
5. The MIL will light for approximatel y 5 seconds. While the MIL lights,
short the DLC terminals again with the special tool. The self-diagnostic
memory is erased if the MIL  goes off and starts blinking.
 • The DLC must be jumped while the MIL lights. If not, the MIL will not
start blinking.
 • Note that the self-diagnostic memory c annot be erased if the ignition switch is turned OFF before the MIL starts blinking.
[1]
[2]
TOOL:
[2] SCS connector 070PZ-ZY30100
[1]
[2]
TOOL:
[2] SCS connector 070PZ-ZY30100
[1]
[2] 
						

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PGM-FI SYSTEMCIRCUIT INSPECTION
INSPECTION AT ECM CONNECTOR
 • Always clean around and keep any foreign material away from the ECM 33P (Black) connector before disconnecting it.
 • A faulty PGM-FI system is often rela ted to poorly connected or corroded
terminals. Check those connections before proceeding.
 • In testing at ECM 33P (Black) connector (wire harness side) terminal, always use the test probe [1]. Inse rt the test probe into the connector
terminal, then attach th e digital multimeter probe to the test probe.
PGM-FI SYMPTOM TROUBLESHOOTING
When the motorcycle has one of these symptoms, check the MIL bl inking, refer to the MIL code index (page 4-7) and begin the
appropriate troubleshooting procedure. If t here are MIL blinking stored in the ECM me mory, do the diagnostic procedure for the
symptom, in sequence listed below, until you find cause. TOOL:
[1] Test probe
07ZAJ-RDJA110
[1]
Symptom Diagnosis procedure Also check for
Engine cranks but won’t start
(No MIL blinking) 1. Inspect the IACV (page 7-16).
2. Inspect the fuel supply system (page 7-4).
3. Inspect the ignition system (page 5-4).  • No fuel to injector
– Clogged fuel filter
– Pinched or clogged fuel feed hose
– Faulty fuel pump
– Faulty fuel pump circuits
 • Intake air leak
 • Contaminated/deteriorated fuel
 • Faulty injector
Engine cranks but won’t start
(No fuel pump operation sound 
when the turning the ignition 
ON) 1. ECM power/ground circuits malfunction 
(page 4-49).
2. Inspect the fuel supply system (page 7-4).  • Open circuit in the power input 
and/or ground wire of the ECM
 • Blown main fuse (30 A)
 • Blown FI, IGN fuse (10 A) 
Engine stalls, hard to start, 
rough idling 1. Inspect the engine idle speed (page 3-10).
2. Inspect the IACV (page 7-16).
3. Inspect the fuel supply system (page 7-4).
4. Inspect the battery charging system (page 
19-4).
5. Inspect the ignition system (page 5-4).  • Restricted fuel feed hose
 • Contaminated/deteriorated fuel
 • Intake air leak
 • Faulty MAP sensor
 • Restricted fuel tank breather hose
Afterburn when engine braking 
is used 1. Inspect the PAIR system (page 7-17).
2. Inspect the ignition system (page 5-4).
Backfiring or misfiring during 
acceleration Inspect the ignition system (page 5-4).
Poor performance (driveability) 
and poor fuel economy 1. Inspect the fuel supply system (page 7-4).
2. Inspect the air cleaner element (page 3-4).
3. Inspect the ignition system (page 5-4).  • Faulty pressure regulator (fuel 
pump)
 • Faulty injector
 • Faulty MAP sensor
Idle speed is below 
specifications or fast idle too low 
(No MIL blinking) 1. Inspect the engine idle speed (page 3-10).
2. Inspect the IACV (page 7-16).
3. Inspect the ignition system (page 5-4).
Idle speed is above 
specifications or fast idle too 
high (No MIL blinking) 1. Inspect the engine idle speed (page 3-10).
2. Inspect the throttle operation and freeplay 
(page 3-3).
3. Inspect the IACV (page 7-16).
4. Inspect the ignition system (page 5-4).  • Intake air leak
 • Engine top-end problem
 • Air cleaner element condition
MIL never comes ON at all Inspect the MIL circuit (page 4-43).
MIL stays ON
(No DTC set) 1. Inspect the DLC circuit (page 4-43).
2. Inspect the MIL circuit (page 4-43). 
						

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PGM-FI SYSTEM
DTC INDEX
DTC 
(MIL 
blinks) Function Failure Symptom/Fail-safe function Refer 
to 
(DTC)  Refer 
to 
(MIL) 
1-1 (1) MAP sensor circuit low voltage (less than 0.195 V)
 • MAP sensor or its circuit malfunction  • Engine operates normally
 • Pre-program value: 525 mmHg/
700 hPa 4-10
4-29
1-2 (1) MAP sensor circuit high voltage (more than 3.848 V)
 • Loose or poor contact of the sensor unit 
connector
 • MAP sensor or its circuit malfunction  • Engine operates normally
 • Pre-program value: 525 mmHg/
700 hPa 4-11
7-1 (7) ECT sensor circuit low voltage (less than 0.078 V)
 • ECT sensor or its circuit malfunction  • Hard start at a low temperature
  • Pre-program value: 80°C/176°F
 • Cooling fan turns on
4-13
4-30
7-2 (7) ECT sensor circuit high vo
ltage (more than 4.922 V)
 • Loose or poor contact of the ECT sensor 
connector
 • ECT sensor or its circuit malfunction  • Hard start at a low temperature
  • Pre-program value: 80°C/176°F
 • Cooling fan turns on
4-11
8-1 (8) TP sensor circuit low voltage (less than 0.215 V)
 • Loose or poor contact of the sensor unit 
connector
 • TP sensor or its circuit malfunction  • Poor engine acceleration
 • Pre-program value: 0°
4-15
4-32
8-2 (8) TP sensor circuit high voltage (more than 4.922 V)
 • TP sensor or its circuit malfunction  • Poor engine acceleration
 • Pre-program value: 0°
4-16
9-1 (9) IAT sensor circuit low voltage (less than 0.078 V)
 • IAT sensor or its circuit malfunction  • Engine operates normally
 • Pre-program value: 35°C/95°F
4-18
4-33
9-2 (9) IAT sensor circuit high voltage (more than 4.922 V)
 • Loose or poor contact of the sensor unit 
connector
 • IAT sensor or its circuit malfunction  • Engine operates normally
 • Pre-program value: 35°C/95°F
4-18
11-1  (1) VS sensor malfunction
 • Loose or poor contact of the VS sensor 
connector
 • VS sensor or its circuit malfunction  • Engine operates normally
4-18 4-35
12-1  (12) Injector circui
t malfunction
 • Loose or poor contact of the injector connector
 • Injector or its  circuit malfunction  • Engine does not start 
 • Injector, fuel pump and ignition 
coil shut down 4-21 4-36
21-1  (21) O
2 sensor malfunction
  • Loose or poor contact of the O
2 sensor connector
 •O2 sensor or its circuit malfunction  • Engine operates normally
4-23 4-38
29-1  (29) IACV circuit malfunction
 • Loose or poor contact of the IACV connector
 • IACV or its circuit malfunction  • Engine stalls, hard to start, 
rough idling  4-24 4-39
33-2 (– ) ECM EEPROM malfunction
 • Engine operates normally
4-26 –
54-1  (54) Bank angle sensor circuit low voltage (less than 
0.35 V)
 • Bank angle sensor or its circuit malfunction
 • Engine operates normally
 • Bank angle sensor does not 
operate.
(The engine keeps running 
when the vehicle falls.) 4-27
4-41
54-2  (54) Bank angle sensor circuit high voltage (more than 
4.5 V)
 • Loose or poor contact of the bank angle sensor 
connector
 • Bank angle sensor or its circuit malfunction  • Engine operates normally
 • Bank angle sensor does not 
operate.
(The engine keeps running 
when the vehicle falls.) 4-28 
						

							4-8
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PGM-FI SYSTEM
SENSOR UNIT POWER LINE 
INSPECTION
BEFORE DTC TROUBLESHOOTING
 • When the DTC displays 1-1, 1-2, 8-1, 8-2, 9-1 and 9-
2, check the following before DTC troubleshooting.
 • Before starting the inspection, check for loose or  poor contact on the sensor unit 5P connector and ECM
33P (Black) connector.
Probable cause
 • Open circuit in Yellow/red wire between the sensor unit and ECM
 • Open circuit in Green/white wire between the sensor unit and ECM
 • Faulty ECM
1. Sensor Unit Power Input Voltage Inspection
Turn the ignition switch OFF.
Disconnect the sensor unit 5P connector [1] (page
7-11).
Turn the ignition switch ON and engine stop switch
.
Measure the voltage at the wire harness side.
If the voltage within 4.75 – 5.25 V?
YES – Turn the ignition switch OFF. Connect the
sensor unit 5P connector and start the
DTC troubleshooting (page 4-10).
NO – GO TO STEP 2.
2. Sensor Unit Input Voltage Line Open Circuit Inspection
Turn the ignition switch OFF.
Disconnect the ECM 33P (Black) connector [1]
(page 4-50).
Check for continuity between the ECM 33P (Black)
connector and sensor unit 5P connector [2] of the
wire side.
Is there continuity?
YES – Replace the ECM with a know good one
and recheck.
NO –  • Open circuit in Yellow/red wire
Y/R
G/W
5 V
ECM
SENSOR UNIT
Connection: Yellow/red (+) – Green/white (–)
Standard: 4.75 – 5.25 V
Y/R G/W
[1]
Connection: Yellow/red – Yellow/red
Green/white – Green/white
TOOL:
Test probe 07ZAJ-RDJA110
Y/R
G/W
[2][1]
Y/R
G/W 
						

							4-9
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PGM-FI SYSTEM
 • Open circuit in Green/white wire
BEFORE MIL TROUBLESHOOTING
 • When the MIL blinks 1, 8 and 9 times, check thefollowing before MIL troubleshooting.
 • Before starting the inspection, check for loose or  poor contact on the sensor unit 5P connector and ECM
33P (Black) connector.
Probable cause
 • Open circuit in Yellow/red wire between the sensor unit and ECM
 • Open circuit in Green/white wire between the sensor unit and ECM
 • Faulty ECM
1. Sensor Unit Power Input Voltage Inspection
Turn the ignition switch OFF.
Disconnect the sensor unit 5P connector [1] (page
4-44).
Turn the ignition switch ON and engine stop switch
.
Measure the voltage at the wire harness side.
If the voltage within 4.75 – 5.25 V?
YES – Turn the ignition switch OFF. Connect the
sensor unit 5P connector and start the MIL
troubleshooting (page 4-29).
NO – GO TO STEP 2.
2. Sensor Unit Input Voltage Line Open Circuit Inspection
Turn the ignition switch OFF.
Disconnect the ECM 33P (Black) connector [1]
(page 4-50).
Check for continuities between the ECM 33P
(Black) connector and sensor unit 5P connector [2]
of the wire side.
Is there continuity?
YES – Replace the ECM with a know good one
and recheck.
NO –  • Open circuit in Yellow/red wire
 • Open circuit in Green/white wire
Y/R
G/W
5 V
ECM
SENSOR UNIT
Connection: Yellow/red (+) – Green/white (–)
Standard: 4.75 – 5.25 V
Y/R G/W
[1]
Connection: Yellow/red – Yellow/red
Green/white – Green/white
TOOL:
Test probe 07ZAJ-RDJA110
Y/R
G/W
[2][1]
Y/R
G/W 
						

							4-10
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PGM-FI SYSTEM
DTC TROUBLESHOOTING
DTC 1 (MAP SENSOR) 
Probable cause
 • Open circuit in Yellow/red wire between the sensorunit and ECM
 • Open or short circuit in Light green/black wire between the sensor unit and ECM
 • Open circuit in Green/white wire between the sensor unit and ECM
 • Faulty sensor unit
 • Faulty ECM
DTC 1-1 (MAP SENSOR LOW VOLTAGE)
1. MAP sensor system inspection
Turn the ignition switch ON and engine stop switch
.
Check the MAP sensor with the HDS pocket tester.
Is about 0 V indicated?
YES – GO TO STEP 2.
NO – Intermittent failure
2. 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 3.
NO – Replace or repair the abnormal circuit.
3. MAP 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 4.
Y/R
G/W
5 V
ECM
SENSOR UNIT 
(MAP SENSOR)
5 V
Lg/Bl
Connection:
Light green/black (+) – Green/white (–)
Standard: 4.75 – 5.25 V
G/W
[1]
Lg/Bl 
						

							4-11
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PGM-FI SYSTEM
4. MAP Sensor Output Line Short CircuitInspection
Turn the ignition switch OFF.
Disconnect the ECM 33P (Black) connector.
Check for continuity between the sensor unit 5P
connector [1] terminal of the wire side and ground.
Is there continuity?
YES – Short circuit in Light green/black wire
NO – GO TO STEP 5.
5. MAP Sensor Inspection Replace the sensor unit with a known good one
(page 4-44).
Erase the DTC’s (page 4-5).
Turn the ignition switch OFF.
Connect the sensor unit 5P connector.
Turn the ignition switch ON and engine stop switch
.
Check the MAP sensor with the HDS pocket tester.
Is DTC 1-1 indicated?
YES – Replace the ECM with a known good one,
and recheck.
NO – Faulty original sensor unit (MAP sensor)
DTC 1- 2 (MAP SENSOR HIGH VOLTAGE)
1. MAP Sensor System Inspection 1 Turn the ignition switch ON and engine stop switch
.
Check the MAP sensor with the HDS pocket tester.
Is about 5 V indicated?
YES – GO TO STEP 2.
NO –  • Intermittent failure
 • Loose or poor contact on the sensor
unit 5P connector
2. 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 3.
NO – Replace or repair the abnormal circuit.
Connection: Light green/black – Ground
Lg/Bl
[1]