Honda CBR125RW - Service manual > MIL Troubleshooting

Engine / Fuel System (PGM-FI) / MIL Troubleshooting

MIL 1 BLINK (MAP SENSOR)

1. Sensor Unit Power Line Inspection

Check the sensor unit power line inspection.

Is the sensor unit power line normal?

YES - GO TO STEP 2.

NO - Replace or repair of the abnormal circuit.

2. MAP Sensor Output Voltage Inspection

Turn the ignition switch ON (and engine stop switch "": CM and U type).

Measure the voltage at the test harness terminals.

Connection: 27 (+) - 4 (-)

Standard: 2.6 - 3.2 V (20ºC/68ºF)

Is the voltage within 2.6 - 3.2 V (20ºC/68ºF)?

YES -

NO -

Fuel System (PGM-FI)

3. MAP Sensor Output Line Open Circuit Inspection 1

Turn the ignition switch OFF.

Disconnect the sensor unit 5P connector.

Turn the ignition switch ON (and engine stop switch "": CM and U type).

Measure the voltage at the sensor unit 5P connector of the wire side.

Connection: Light green/yellow (+) - Green/orange (-)

Standard: 3.80 - 5.25 V

Is the voltage within 3.80 - 5.25 V?

YES - Faulty sensor unit (MAP sensor)

NO - Open circuit in Light green/yellow wire

Fuel System (PGM-FI)

4. MAP Sensor Output Line Short Circuit Inspection

Turn the ignition switch OFF.

Disconnect the sensor unit 5P connector.

Check for continuity between the sensor unit 5P connector terminal of the wire side and ground.

Connection: Light green/yellow - Ground

Is there continuity?

YES - Short circuit in Light green/yellow wire

NO - GO TO STEP 5.

Fuel System (PGM-FI)

5. MAP Sensor Output Line Open Circuit Inspection 2

Check the continuity between the ECM test harness and sensor unit 5P connector of the wire side.

Connection: 27 - Light green/yellow

Is there continuity?

YES - Faulty sensor unit (MAP sensor)

NO - Open circuit in Light green/yellow wire

Fuel System (PGM-FI)

MIL 7 BLINKS (ECT SENSOR)

1. ECT Sensor Input Voltage Inspection

Turn the ignition switch OFF.

Disconnect the ECT sensor 3P connector.

Turn the ignition switch ON (and engine stop switch "": CM and U type).

Measure the voltage at the ECT sensor connector of the wire side and ground.

Connection:

Yellow/blue (+) - Ground (-)
Standard: 4.75 - 5.25 V

Is the voltage within 4.75 - 5.25 V?

YES - GO TO STEP 3.

NO - GO TO STEP 2.

Fuel System (PGM-FI)

2. ECT Sensor Short Circuit Inspection

Turn the ignition switch OFF.

Check for continuity between the ECT sensor connector of the wire side and ground.

Connection: Yellow/blue - Ground

Is there continuity?

YES - Short circuit in Yellow/blue wire

NO - GO TO STEP 3.

Fuel System (PGM-FI)

3. ECT Sensor Resistance Inspection

Turn the ignition switch OFF.

Measure the resistance at the ECT sensor terminals.

Connection: Yellow/blue - Green/orange
Standard: 2.3 - 2.6 kΩ (20ºC/68ºF)

Is the resistance within 2.3 - 2.6 kΩ (20ºC/68ºF)?

YES - GO TO STEP 4.

NO - Faulty ECT sensor

Fuel System (PGM-FI)

4. ECT Sensor Open Circuit Inspection

Connect the ECM test harness to ECM 33P connector.

Check the continuities between the ECM test harness and ECT 3P sensor connector of the wire side.

Connection:

24 - Yellow/blue
4 - Green/orange

Are there continuities?

YES - GO TO STEP 5.

NO -

Fuel System (PGM-FI)

5. ECT Sensor Output Voltage Inspection

Connect the ECT sensor 3P connector.

Turn the ignition switch ON (and engine stop switch "": CM and U type).

Measure the voltage at the ECM test harness terminals.

Connection: 24 (+) - 4 (-)
Standard: 2.7 - 3.1 V (20ºC/68ºF)

Is the voltage within 2.7 - 3.1 V (20ºC/68ºF)?

YES -

NO - Replace the ECM with a known good one, and recheck.

Fuel System (PGM-FI)

MIL 8 BLINKS (TP SENSOR)

1. Sensor Unit Power Line Inspection

Check the sensor unit power line inspection.

Is the sensor unit power line normal?

YES - GO TO STEP 2.

NO - Replace or repair the abnormal circuit.

2. TP Sensor Output Voltage

Turn the ignition switch ON (and engine stop switch "": CM and U type).

Measure the TP sensor output voltage at the ECM test harness terminals.

Connection: 5 (+) - 4 (-)

Standard:

0.29 - 0.71 V (throttle fully closed)
4.13 - 4.76 V (throttle fully opened)

Is there standard voltage?

YES -

NO - GO TO STEP 3.

Fuel System (PGM-FI)

3. TP Sensor Output Line Short Circuit Inspection

Turn the ignition switch OFF.

Disconnect the sensor unit 5P connector.

Check for continuity between the sensor unit 5P connector of the wire side and ground.

Connection: Yellow/black - Ground

Is there continuity?

YES - Short circuit in Yellow/black wire

NO - GO TO STEP 4.

Fuel System (PGM-FI)

4. TP Sensor Voltage Input Line Open Circuit Inspection

Check for continuity between the sensor unit 5P connector of the wire side and ECM test harness.

Connection: 5 - Yellow/black

Is there continuity?

YES - Faulty sensor unit (TP sensor)

NO - Open circuit in Yellow/black wire

Fuel System (PGM-FI)

MIL 9 BLINKS (IAT SENSOR)

1. Sensor Unit Power Line Inspection

Check the sensor unit power line inspection.

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 1

Turn the ignition switch ON (and engine stop switch "": CM and U type).

Measure the voltage at the ECM test harness terminals.

Connection: 14 (+) - 4 (-)
Standard: 2.7 - 3.1 V (20ºC/68ºF)

Is the voltage within 2.7 - 3.1 V (20ºC/68ºF)?

YES -

NO - GO TO STEP 3.

Fuel System (PGM-FI)

3. IAT Sensor Output Voltage Inspection 2

Turn the ignition switch OFF.

Disconnect the sensor unit 5P connector.

Turn the ignition switch ON (and engine stop switch "": CM and U type).

Measure the voltage at the sensor unit 5P connector of the wire side.

Connection: Gray/blue (+) - Green/orange (-)

Standard: 4.75 - 5.25 V

Is the voltage within 4.75 - 5.25 V?

YES - GO TO STEP 6.

NO - GO TO STEP 4.

Fuel System (PGM-FI)

4. IAT Sensor Voltage Input Line Short Circuit Inspection

Check for continuity between the sensor unit 5P connector of the wire side and ground.

Connection: Gray/blue - Ground

Is there continuity?

YES - Short circuit in Gray/blue wire

NO - GO TO STEP 5.

Fuel System (PGM-FI)

5. IAT Sensor Voltage Input Line Open Circuit Inspection

Check for continuity at the Gray/blue wire between the sensor unit 5P connector of the wire side and ECM test harness.

Connection: 14 - Gray/blue

Is there continuity?

YES - GO TO STEP 6.

NO - Open circuit in Gray/blue wire

Fuel System (PGM-FI)

6. IAT Sensor Resistance Inspection

Turn the ignition switch OFF.

Connect the sensor unit 5P connector.

Measure the resistance at the ECM test harness terminals (at 20ºC/68ºF).

Connection: 14 - 4

Standard: 1.13 - 1.88 kΩ (20ºC/68ºF)

Is the resistance within 1.13 - 1.88 kΩ (20ºC/ 68ºF)?

YES - Replace the ECM with a known good one, and recheck.

NO - Faulty sensor unit (IAT sensor)

Fuel System (PGM-FI)

MIL 12 BLINKS (INJECTOR)

1. Injector Input Voltage Inspection

Turn the ignition switch OFF.

Disconnect the injector 2P connector.

Turn the ignition switch ON (and engine stop switch "": CM and U type).

Measure the voltage between the injector 2P connector of the wire side and ground.

Connection: Black/white (+) - Ground (-)

Standard: Battery voltage

Does the standard voltage exist?

YES - GO TO STEP 2.

NO - Open or short circuit in Black/white wire

Fuel System (PGM-FI)

2. Injector Signal Line Short Circuit Inspection

Turn the ignition switch OFF.

Check for continuity between the injector 2P connector of the wire side and ground.

Connection: Pink/green - Ground

Is there continuity?

YES - Short circuit in Pink/green wire

NO - GO TO STEP 3.

Fuel System (PGM-FI)

3. Injector Resistance Inspection

Measure the resistance between the injector 2P connector terminals.

Standard: 9 - 12 Ω (20ºC/68ºF)

Is the resistance within 9 - 12 Ω (20ºC/68ºF)?

YES - GO TO STEP 4.

NO - Faulty injector

Fuel System (PGM-FI)

4. Injector Signal Line Open Circuit Inspection

Connect the ECM test harness to the ECM 33P connector.

Check the continuity between the ECM test harness and injector 2P connector of the wire side.

Connection: 16 - Pink/green

Is there continuity?

YES - Replace the ECM with a known good one, and recheck.

NO - Open circuit in Pink/green wire

Fuel System (PGM-FI)

MIL 21 BLINKS (O2 SENSOR)

 

1. O2 Sensor System Inspection

Turn the ignition switch ON (and engine stop switch "": CM and U type).

Start the engine and warm up the engine up to coolant temperature is 80ºC (176ºF).

Test-ride the motorcycle and recheck the MIL blinking.

Does the MIL blink 21 times?

YES - GO TO STEP 2.

NO - Intermittent failure

2. O2 Sensor Short Circuit Inspection

Turn the ignition switch OFF.

Disconnect the O2 sensor 2P connector.

Check for continuity between the O2 sensor 2P connector of the wire side and ground.

Connection: Black/orange - Ground

Is there continuity?

YES - Short circuit in Black/orange wire

NO - GO TO STEP 3.

Fuel System (PGM-FI)

3. O2 Sensor Open Circuit Inspection

Connect the ECM test harness to the ECM 33P connector.

Check the continuity between the ECM test harness and O2 sensor 2P connector of the wire side.

Connection: 3 - Black/orange

Is there continuity?

YES - GO TO STEP 4.

NO - Open circuit in Black/orange wire

Fuel System (PGM-FI)

4. O2 Sensor Inspection

Replace the O2 sensor and O2 sensor cord with a known good one.

Disconnect the ECM test harness and connect the ECM 33P connector.

Turn the ignition switch ON (and engine stop switch "": CM and U type).

Start the engine and warm up the engine up to coolant temperature is 80ºC (176ºF).

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 O2 sensor and/or O2 sensor cord

MIL 29 BLINKS (IACV)

1. IACV Resistance Inspection

Turn the ignition switch OFF.

Disconnect the IACV 4P connector.

Measure the resistance at the IACV 4P connector terminals.

Connection:

Blue/black - Blue/red
Pink/black - Brown/yellow

Standard: 110 - 150 Ω (25ºC/77ºF)

Is the resistance within 110 - 150 Ω (25ºC/77ºF)?

YES - GO TO STEP 2.

NO - Faulty IACV

Fuel System (PGM-FI)

2. IACV Short Circuit Inspection

Check for continuities between the IACV 4P connector of the wire side and ground.

Connection:

Blue/black - Ground
Pink/black - Ground
Brown/yellow - Ground
Blue/red - Ground

Is there continuity?

YES -

NO - GO TO STEP 3.

Fuel System (PGM-FI)

3. IACV Open Circuit Inspection

Connect the ECM test harness to ECM 33P connector.

Check the continuities between the ECM test harness and IACV 4P connector of the wire side.

Connection:

20 - Pink/black
21 - Blue/black
31 - Brown/yellow
32 - Blue/red

Is there continuity?

YES - Replace the ECM with a known good one, and recheck.

NO -

Fuel System (PGM-FI)

MIL 54 BLINKS (BANK ANGLE SENSOR)

1. Bank Angle Sensor Power Input Voltage Inspection

Turn the ignition switch OFF.

Disconnect the bank angle sensor 3P connector.

Turn the ignition switch ON (and engine stop switch "": CM and U type).

Measure the voltage at the bank angle sensor connector of the wire side.

Connection: White/red (+) - Green/orange (-)

Standard: 4.75 - 5.25 V

Is there within 4.75 - 5.25 V?

YES - GO TO STEP 4.

NO - GO TO STEP 2.

Fuel System (PGM-FI)

2. Bank Angle Sensor Input Voltage Line Short Circuit Inspection

Turn the ignition switch OFF.

Check the continuity between the bank angle sensor 3P connector of the wire side and ground.

Connection: White/red - Ground

Is there continuity?

YES - GO TO STEP 3.

NO - Short circuit in White/red wire

Fuel System (PGM-FI)

3. Bank Angle Sensor Input Voltage Line Open Circuit Inspection

Connect the ECM test harness to the ECM 33P connector.

Check the continuities between the ECM test harness and bank angle sensor 3P connector of the wire side.

Connection:

6 - White/red
4 - Green/orange

Is there continuity?

YES - Replace the ECM with a known good one, and recheck.

NO -

Fuel System (PGM-FI)

4. Bank Angle Sensor Output Line Short Circuit Inspection

Turn the ignition switch OFF.

Check the continuity between the bank angle sensor 3P connector of the wire side and ground.

Connection: Red/blue - Ground

Is there continuity?

YES - Short circuit in Red/blue wire NO - GO TO STEP 5.

Fuel System (PGM-FI)

5. Bank Angle Sensor Output Line Open Circuit Inspection

Connect the ECM test harness to the ECM 33P connector.

Check the continuity between the ECM test harness and bank angle sensor 3P connector of the wire side.

Connection: 26 - Red/blue

Is there continuity?

YES - Open circuit in Red/blue wire

NO - Inspect the bank angle sensor.

Fuel System (PGM-FI)

MIL CIRCUIT TROUBLESHOOTING

If the engine can be started but the MIL does not come on when the ignition switch is turned ON (and engine stop switch "": CM and U type), check as follows: Check for the combination meter function.

NOTE:

Turn the ignition switch OFF.

Lift and support the fuel tank.

Open the rubber sheet.

Disconnect the ECM 33P connector.

Ground the White/blue wire terminal of the wire harness side ECM 33P connector with a jumper wire.

Connection: 18 (White/black) - Ground

TOOL: Test probe 07ZAJ-RDJA110

Fuel System (PGM-FI)

Turn the ignition switch ON (and engine stop switch "": CM and U type) the MIL should come on.

Fuel System (PGM-FI)

See also:

 Honda CBR125RW - Service manual > DTC Troubleshooting

DTC 1-1 (MAP SENSOR LOW VOLTAGE) 1. MAP Sensor System Inspection Turn the ignition switch ON (and engine stop switch "": CM and U type).

 Honda CBR125RW - Service manual > Fuel

FUEL LINE INSPECTION FUEL PRESSURE RELIEVING/QUICK CONNECT FITTING REMOVAL Do not bend or twist fuel feed hose. Before disconnecting fuel feed hose, relieve pressure from the system as follows.

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