Honda CBR125RW - Service manual > DTC Index

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 connector.

1. Sensor Unit Power Input Voltage Inspection

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 wire side.

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

Standard: 4.75 - 5.25 V

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.

NO - GO TO STEP 2.

2. Sensor Unit Input Voltage Line Short Circuit Inspection

Turn the ignition switch OFF.

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

Connection: White/red - Ground

Is there continuity?

YES - Short circuit in White/red wire

NO - GO TO STEP 3.

3. Sensor Unit Power Line Open Circuit Inspection

Disconnect the ECM 33P connector.

Check for continuities at the White/red and Green/orange wires between the sensor unit 5P and ECM 33P connectors.

Connection:

6 (Yellow/red) - White/red
4 (Green/orange) - Green/orange

TOOL: Test probe 07ZAJ-RDJA110

Is there continuity?

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

NO -

• Open circuit in White/red wire
• Open circuit in Green/orange wire

BEFORE MIL TROUBLESHOOTING

• When the MIL blinks 1, 8 and 9 times, check the following before MIL troubleshooting.
• Before starting the inspection, check for loose or poor contact on the sensor unit 5P connector and ECM 33P connector.

1. Sensor Unit Power Input Voltage Inspection 1

Turn the ignition switch OFF.

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

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

Measure the voltage at the test harness terminals.

Connection: 6 (+) - 4 (-)

Standard: 4.75 - 5.25 V

Is the voltage within 4.75 - 5.25 V?

YES - GO TO STEP 2.

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

2. Sensor Unit Power Input 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 wire side.

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

Standard: 4.75 - 5.25 V

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.

NO - GO TO STEP 3.

3. Sensor Unit Input Voltage Line Short Circuit Inspection

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

Connection: White/red - Ground

Is there continuity?

YES - Short circuit in White/red wire

NO - GO TO STEP 4.

4. Sensor Unit Input Voltage Line Open Circuit Inspection

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

Connection:

6 - White/red
4 - Green/orange

Is there continuity?

YES - Intermittent failure

NO -

• Open circuit in White/red wire
• Open circuit in Green/orange wire

See also: