Page 135 - 2019 SHOP MANUAL CRF1000/A/D

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PGM-FI SYSTEM
DTC 23 (O2 SENSOR HEATER)

ECM/PCM

From FI relay

O2 SENSOR HEATER
Bl/W
W

W W

Probable cause
• Open circuit in the Black/white wire between the FI
relay and O2 sensor
• Open or short circuit in the White wire between the
O2 sensor and ECM/PCM
• Faulty O2 sensor
• Faulty ECM/PCM
DTC 23-1 (O2 SENSOR HEATER)

• Before starting the inspection, check for loose or
poor contact on the O2 sensor 4P (Black) and ECM/
PCM 33P (Gray) connectors, and recheck the DTC.
1. Recheck DTC
Erase the DTC (page 4-6).
Start the engine and check the DTC with the MCS.
Is DTC 23-1 indicated?
YES – GO TO STEP 2.
NO – Intermittent failure
2. O2 Sensor Heater Resistance Inspection
Turn the ignition switch OFF.
Disconnect the O2 sensor 4P (Black) connector [1]
(page 2-17).
Measure the resistance at the sensor side 4P
(Black) connector [1].
Connection: White – White

Standard: 6.7 – 10.5 Ω (20°C/68°F)
Is the resistance within standard value? W W
YES – GO TO STEP 3.
NO – Faulty O2 sensor

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