DTC P0111: Intake Air Temperature (IAT) Sensor Circuit Range/Performance Problem

1. Turn ignition off. Disconnect IAT sensor harness connector. Check for poor terminal contact at IAT sensor connector. If poor terminal contact is found, repair as necessary and retest system. If connection is okay, remove IAT sensor and go to next step.
2. Measure resistance between IAT sensor terminals while immersed in a container of water. Heat water slowly and ensure resistance changes as specified. See Fig 1 . If resistance is not as specified, replace IAT sensor. If resistance is as specified, go to next step.
3. Disconnect PCM harness connectors. Check for poor connection at PCM 16-pin harness connector "B". On Esteem, check terminals No. 9 (Green/Red wire) and No. 14 (Gray/Red wire). On Swift, check terminals No. 9 (Light Green/Black wire) and No. 14 (Gray wire). If connections are okay, check circuit wiring for high resistance between IAT sensor and PCM. Repair as necessary. If wiring checks okay, check for an intermittent problem or faulty PCM. Go to TROUBLE SHOOTING - NO CODES article.

Fig 1: Identifying Intake Air Temperature Sensor Resistance (Typical)

Courtesy of SUZUKI OF AMERICA CORP.