Page 127 - 2019 SHOP MANUAL CRF1000/A/D

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PGM-FI SYSTEM
DTC 9 (IAT SENSOR)
ECM/PCM

5 V

IAT SENSOR
Br/R

Gr/Bl

Probable cause
• Open or short circuit in the Brown/red wire between
the IAT sensor and ECM/PCM
• Open circuit in the Gray/black wire between the IAT
sensor and ECM/PCM
• Faulty IAT sensor
• Faulty ECM/PCM
DTC 9-1 (IAT SENSOR LOW VOLTAGE)
1. IAT Sensor System Inspection
Check the IAT sensor with the MCS.
Is about 0 V indicated?
YES – GO TO STEP 2.
NO – Intermittent failure
2. IAT Sensor System Inspection with Connector
Disconnected
Turn the ignition switch OFF.
Disconnect the IAT sensor 2P (Blue) connector
(page 4-41).
Check the IAT sensor with the MCS.
Is about 0 V indicated?
YES – GO TO STEP 3.
NO – Faulty sensor unit (IAT sensor)
3. IAT Sensor Output Line Short Circuit Inspection
Turn the ignition switch OFF.
Disconnect the ECM/PCM 33P (Gray) connector [1]
(page 4-39).
Check for continuity between the wire harness side
2P (Blue) connector [1] and ground.
Connection: Brown/red – Ground
Br/R
Is there continuity?
YES – Short circuit in the Brown/red wire
NO – Replace the ECM/PCM with a known good
one (page 4-39) and recheck.

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