Pinpoint Tests DA: Intake Air Temperature (IAT) Sensor: Introduction

WARNING: TO PREVENT THE RISK OF HIGH-VOLTAGE SHOCK, ALWAYS FOLLOW PRECISELY ALL WARNINGS AND SERVICE INSTRUCTIONS, INCLUDING INSTRUCTIONS TO DEPOWER THE SYSTEM. THE HIGH-VOLTAGE SYSTEM UTILIZES APPROXIMATELY 300 VOLTS DC, PROVIDED THROUGH HIGH-VOLTAGE CABLES TO ITS COMPONENTS AND MODULES. THE HIGH-VOLTAGE CABLES AND WIRING ARE IDENTIFIED BY ORANGE HARNESS TAPE OR ORANGE WIRE COVERING. ALL HIGH-VOLTAGE COMPONENTS ARE MARKED WITH HIGH-VOLTAGE WARNING LABELS WITH A HIGH-VOLTAGE SYMBOL. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN SERIOUS PERSONAL INJURY OR DEATH.

This pinpoint test is intended to diagnose the following:

integrated mass airflow (MAF)/intake air temperature (IAT) sensor (12B579)
harness circuits: IAT and SIGRTN
PCM (12A650)

Voltage values calculated for VPWR equals 5 volts. These values can vary by 15% due to sensor and VPWR variations.

Fig 1: Intake Air Temperature Sensor Voltage Graph

Courtesy of FORD MOTOR CO.

Fig 2: Mass Airflow/Intake Air Temperature (MAF/IAT) Sensor Connector

Courtesy of FORD MOTOR CO.

Pin	Circuit
4	SIGRTN (Signal Return)
2	IAT (Intake Air Temperature)
3	VPWR (Vehicle Power)

Fig 3: Powertrain Control Module (PCM) Connector

Courtesy of FORD MOTOR CO.

Pin	Circuit
E1, E3, E6	SIGRTN (Signal Return)
E17	IAT (Intake Air Temperature)