Pinpoint Test KT: Motor Electronics Cooling System (MECS) Pump: 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.

NOTE: When using Output State Control for the MECS pump, do not leave the pump off for more than 2 minutes with the ignition ON.

NOTE: Under normal operating conditions, the motor electronics cooling system should be able to maintain a temperature of approximately 11°C (20°F) over ambient temperature while driving.

This pinpoint test is intended to diagnose the following:

MECS pump relay (14B192)
harness circuits: MECS pump, vehicle power (VPWR)
powertrain control module (PCM) (12A650)

Fig 1: MECS Pump Relay Connector

Courtesy of FORD MOTOR CO.

MECS PUMP RELAY CONNECTOR PINS REFERENCE CHART

Pin	Circuit
3	VPWR (Vehicle Power)
2	MECSPR (Motor Electronics Cooling System Pump Relay)

Fig 2: Powertrain Control Module (PCM) Connector

Courtesy of FORD MOTOR CO.

PCM CONNECTOR PINS REFERENCE CHART

Pin	Circuit
149	MECSPR (Motor Cooling System Pump Relay