PGM-FI MIL 10 blink (BARO sensor) (Honda VTX 1800 C, 2001-2008) [Engine and systems: Fuel and control system]

Turn the ignition switch to "OFF".
↓
Disconnect the BARO sensor 3P connector. Check for loose or poor contact on the BARO sensor connector.
↓
Connect the BARO sensor 3P connector. Place the motorcycle on its side stand. Start the engine and check that the MIL blinks.	Does not blink →	Loose or poor contact on the BARO sensor connector.
↓
1 blink
↓
Turn the ignition switch to "OFF".
↓
Disconnect the BARO sensor 3P connector. Turn the ignition switch to "ON". Measure the voltage at the wire harness side connector. Connection: Yellow/red (+) - Ground (-) Standard: 4.75-5.25 V	Out of range →	Open or short circuit in the Yellow/red wire. Loose or poor contact on the ECM connectors.
↓
Voltage exists
↓
Measure the voltage between the connector terminals of the wire harness side. Connection: Yellow/red (+) - Green/orange (-) Standard: 4.75-5.25 V	Out of range →	Open or short circuit in the Green/orange wire. Loose or poor contact on the ECM connectors.
↓
Voltage exists
↓
Measure the voltage between the terminals of the wire harness side. Connection:Light green/black (+) - Green/orange (-) Standard: 4.75-5.25 V	Out of range →	Open or short circuit in the Light green/black wire. Loose or poor contact on the ECM connectors.
↓
Voltage exists
↓
Turn the ignition switch to "OFF". Connect the BARO sensor 3P connector.
↓
Disconnect the ECM connectors. Connect the test harness to ECM connectors. Turn the ignition switch to "ON".
↓
Measure the voltage at the test harness terminals (page 5-9). Connection: B8 (+) - B1 (-) Standard: 2.7-3.1 V (760 mm Hg/1,013 kPa)	Out of range →	Faulty BARO sensor.
↓
Voltage exists
↓
Replace the ECM with a new one, and inspect it again.

PGM-FI MIL 10 blink (BARO sensor) (Honda VTX1800C)