Pinpoint Test Dc: Mass Air Flow (MAF) Sensor: Introduction

WARNING: THIS VEHICLE IS EQUIPPED WITH HIGH VOLTAGE CABLES, COMPONENTS, AND WIRING. THE HIGH VOLTAGE WARNING LABELS CONTAINING THE HIGH VOLTAGE SYMBOL ARE LOCATED ON EACH HIGH VOLTAGE COMPONENT. HIGH VOLTAGE CABLES AND WIRING ARE ORANGE IN COLOR. CERTIFIED RUBBER INSULATING GLOVES AND A FACE SHIELD MUST BE WORN WHEN WORKING WITH THE HIGH VOLTAGE CABLES, COMPONENTS, OR WIRING. THE IGNITION KEY MUST BE CYCLED TO THE OFF POSITION FOR A MINIMUM OF 5 MINUTES, AND THE HIGH VOLTAGE TRACTION BATTERY SERVICE DISCONNECT PLUG PLACED IN THE SERVICING/SHIPPING POSITION BEFORE DISCONNECTING THE HIGH VOLTAGE CABLES. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY OR DEATH.
DO NOT DISCONNECT, DISABLE, OR TOUCH THE HIGH VOLTAGE CABLES, COMPONENTS, OR WIRING DURING THE MODULE REPROGRAMMING PROCEDURE BECAUSE HIGH VOLTAGE IS PRESENT. THE HIGH VOLTAGE WARNING LABELS CONTAINING THE HIGH VOLTAGE SYMBOL ARE LOCATED ON EACH HIGH VOLTAGE COMPONENT. HIGH VOLTAGE CABLES AND WIRING ARE ORANGE IN COLOR. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY OR DEATH.

This pinpoint test is intended to diagnose the following:

MAF sensor (12B579)
harness circuits: MAF, MAF RTN, vehicle power (VPWR), power ground (PWRGND), IAT, and SIGRTN
powertrain control module (PCM) (12A650)

Fig 1: Mass Air Flow/Intake Air Temperature (MAF/IAT) Sensor Connector

Courtesy of FORD MOTOR CO.

MASS AIR FLOW/INTAKE AIR TEMPERATURE (MAF/IAT) SENSOR CONNECTOR PIN REFERENCE CHART

Pin	Circuit
1	IAT (Intake Air Temperature)
2	SIGRTN (Signal Return)
4	MAF RTN (Mass Air Flow Return)
3	MAF (Mass Air Flow)
5	PWRGND (Power Ground)
6	VPWR (Vehicle Power)

Fig 2: Powertrain Control Module (PCM) Connector

Courtesy of FORD MOTOR CO.

POWERTRAIN CONTROL MODULE (PCM) CONNECTOR PIN REFERENCE CHART

Pin	Circuit
B40	MAF (Mass Air Flow)
B41	MAF RTN (Mass Air Flow Return)