Pinpoint Test QD: Unable To Activate Transmission Control Module (TCM) Self-Test: 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:

unable to communicate with the TCM
incorrect self-test procedure
harness circuits: B+, PWRGND and VPWR

Fig 1: Identifying Transmission Control Module-A Connector Terminals
Courtesy of FORD MOTOR CO.

Pin	Circuit
1, 2	PWRGND (Power Ground)
10, 29, 9	VPWR (Vehicle Power)
40	TCMRC (Transmission Control Module Relay Control)