Ford F150 Pickup. Instruction

SYSTEM TESTS

HOW TO USE SYSTEM TESTS

1. Ensure all non-EEC related faults found while performing basic diagnostic procedures in appropriate

BASIC DIAGNOSTIC PROCEDURES article have been corrected. Follow each test step in order until
fault is found. DO NOT replace any part unless directed to do so. When more than one code is retrieved,
start with first code displayed.

2. System tests ensure electrical circuits are okay before sensors or other components are replaced. Always

test circuits for continuity between sensor and PCM. Test all circuits for short to power, opens or short to
ground. Voltage Reference (VREF) and Voltage Power (VPWR) circuits should be tested with ignition
switch in ON position or as specified in SYSTEM TESTS.

3. If measuring voltage or resistance at PCM and a breakout box is not available, always backprobe PCM

harness connector. See PCM CONNECTOR IDENTIFICATION. DO NOT connect any test light
unless specified in testing procedure. All measurements are made by probing rear of connector (wiring
harness side). Isolate both ends of a circuit and turn ignition switch to OFF position when checking for
shorts or continuity, unless instructed otherwise.

4. Disconnect solenoids and switches from harness before measuring continuity and resistance or applying

voltage. After each repair, check all component connections and repeat QUICK TEST.

5. An open circuit is defined as a resistance measurement of 5 ohms or more. This specification tolerance

may be too high for some items in EEC-V system. If resistance approaches 5 ohms, always clean suspect
connector and coat it with protective dielectric silicone grease. A short is defined as a resistance
measurement of 10 k/ohms or less to ground, unless stated otherwise in system test.

6. If instructed to replace Powertrain Control Module (PCM) after performing a system test, new PCM must

be programmed. See PROGRAMMING PCM.

TEST A: NO-START

Diagnostic Aids

Enter this test only when all steps under QUICK TEST have been successfully completed and engine still does
not start or if directed here from another test or chart. This test is only intended to diagnose:

Powertrain Control Module (PCM)

NOTE:

All references to 2V or 4V following an engine size or model is 2 or 4 valves per
cylinder.

NOTE:

After each service or repair procedure has been completed, reconnect all
components. Clear DTCs and repeat QUICK TEST procedures to ensure all EEC-
V systems are working properly and DTCs are no longer present.

WARNING:

Stop this test at first sign of a fuel leak. DO NOT allow smoking or an
open flame in vicinity of vehicle during these tests.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - CNG, Flex-Fuel & Gasoline

Ford F150 Pickup. Instruction - part 1457