Introduction

ESA is a PC-based diagnostic tool that detects fault codes and helps troubleshoot the new multiplexed electrical system. ESA communicates

over a data-link adapter (DLA) to the vehicle ICU/CECU.

ESA will:

• Verify instrumentation functionality

• Read fault codes from components

• Diagnose the problem using information on

ServiceNet

The following chart provides a listing of possible ICU/CECU diagnostic trouble codes (DTCs) and links to their corresponding troubleshooting

procedures.

Fuel Filter Restriction Pressure Gauge

Inoperative

DTC1603 and DTC1604

Symptom: Fuel filter restriction gauge inoperative.

All other gauges are operational.

The Fuel Filter Restriction Gauge uses an electronic transducer (sensor) to monitor vacuum pressure and converts it into a voltage output that

is sent to the instrumentation system. The output voltage of the sensor is proportional to the vacuum it is sensing.

The following procedures have been developed to assist the technician in diagnosing multiplexed instrumentation problems using the Electronic

Service Analyst (ESA) hardware/software diagnostic tool. It is assumed the service technician performing instrumentation repairs is knowledgeable about how to use ESA.