Pinpoint Test DC: Mass Air Flow (MAF) 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 HYBRID 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:
- MAF sensor (12B579)
- harness circuits: MAF, MAF RTN, vehicle power (VPWR), power ground (PWRGND), IAT, and SIGRTN
- powertrain control module (PCM) (12A650)
MAF/IAT SENSOR CONNECTOR PINS 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) |
PCM CONNECTOR PINS REFERENCE CHART
| Pin | Circuit |
|---|---|
| B40 | MAF (Mass Air Flow) |
| B41 | MAF RTN (Mass Air Flow Return) |