4x4 Low/Transmission Control TCIL-TCS-TCSM

1994 PCED OBDI-A

SECTION 6A: EEC-IV Pinpoint Test
Procedures

TB: 4x4 Low/Transmission Control TCIL-TCS-TCSM
Introduction

Note

You should enter this Pinpoint Test only when you have been directed here from Diagnostic Routines, Section 2A.

Remember

This Pinpoint Test is not intended to diagnose components in the transmission. To prevent the replacement of good components, be aware that the following non-EEC areas may be at fault:

Engine

Performance, vacuum, cooling

Electrical

Charging system

Transmission

Hydraulic fluid, friction elements, cooling
Transfer case linkage
Transfer case internal damage

This Pinpoint Test is intended to diagnose only the following:

Harness Circuits: 4x4 LOW, TCIL, TCS, TCSM
Powertrain Control Module (PCM) (12A650) or (12B565 on 7.3L Diesel)

Description

The 4x4 Low Switch is an input used by the Powertrain Control Module, which, when closed, allows the use of a secondary shift schedule while in the low range.

The Transmission Control Switch (TCS) allows the vehicle operator to disengage the overdrive feature when desired.

The Transmission Control Switch Module (TCSM) monitors the Transmission Control Switch (TCS) on the 5.0L AODE Mustang. The TCSM informs the PCM of the vehicle operator's request to disengage the overdrive feature and also controls the Transmission Control Indicator Light (TCIL).

The Transmission Control Indicator Lamp (TCIL) informs the vehicle operator of the Overdrive Range Status "ON" or "OFF" and also informs the operator of certain transmission sensor/actuator malfunctions by flashing the TCIL.