Ford F150 Pickup. Instruction — part 1381

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:

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AFCM

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Circuitry

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PCM Calibration

Testing

1) Check The AFCM SCP Circuits

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Key off.

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Disconnect the AFCM connector C1427.

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Measure the resistance between the AFCM connector C1427 terminal No. 87, harness side and the
DLC connector C251 terminal No. 2, harness side. See CONNECTOR IDENTIFICATION .

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Measure the resistance between the AFCM connector C1427 terminal No. 88, harness side and the
DLC connector C251 terminal No. 10, harness side.

Are the resistances less than 5 ohms? If yes, go to next step. If no, repair the circuit in question.

2) Check The PCM SCP Circuits

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Disconnect PCM connector C175.

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Measure the resistance between the AFCM connector C1427 terminal No. 87, harness side and the
PCM connector C175 terminal No. 16, harness side. See CONNECTOR IDENTIFICATION .

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Measure the resistance between the AFCM connector C1427 terminal No. 88, harness side and the
PCM connector C175 terminal No. 15, harness side.

Are the resistances less than 5 ohms? If yes, go to next step. If no, repair the circuit in question.

3) Check The PCM Configuration

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Reconnect the PCM connector C175.

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Reconnect the AFCM connector C1427.

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Check the PCM configuration. See PROGRAMMING .

Is the PCM configured correctly? If yes, go to next step. If no, calibrate the PCM or replace if necessary.
See PROGRAMMING .

4) Check For Correct AFCM Operation

NOTE:

During bi-fuel diagnostics, intermittent failures are possible. Perform wiggle
test and tap lightly on relays during testing. Ensure vehicle has CNG before
continuing with diagnostics.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - Bi-Fuel - Gasoline/CNG

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Disconnect the AFCM.

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Check for corrosion and pushed out pins.

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Connect the AFCM connector and make sure it is seated correctly.

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Operate the system and verify the concern is still present.

Is the concern still present? If yes, install a new AFCM. If no, the system is operating correctly at this
time. Concern may have been caused by a loose or corroded connector.

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - Bi-Fuel - Gasoline/CNG

2003 ENGINE PERFORMANCE

Self-Diagnostics - Bi-Fuel - Gasoline/LPG

INTRODUCTION

This article contains Bi-Fuel system Continuous Memory DTC, circuit and component diagnostics only. For
diagnostic information not included within this article, see SELF-DIAGNOSTICS - CNG, FLEX-FUEL &
GASOLINE article. If no DTCs are present or only pass codes are found during self-diagnostics, proceed to
TROUBLE SHOOTING - NO CODES - BI-FUEL - GASOLINE/LPG article for diagnosis by symptom. If
symptom tests check okay, perform all basic diagnostic procedures in BASIC DIAGNOSTIC PROCEDURES
- TRUCKS - EXCEPT DIESEL article.

SELF-DIAGNOSTIC SYSTEM

DIAGNOSTIC FORMATS

QUICK TEST and SYSTEM TESTS are diagnostic formats used to test and service EEC-V system. QUICK
TEST allows technician to identify faults and retrieve Diagnostic Trouble Codes (DTC). SYSTEM TESTS are
used to check circuits, sensors and actuators.

Before starting any system test, follow all steps under QUICK TEST to determine appropriate system test to
perform. If vehicle passes QUICK TEST and no driveability symptoms or intermittent faults exist, EEC-V
system is okay.

DIAGNOSTIC TROUBLE CODES

During QUICK TEST, 3 types of DTC may be retrieved: Key On Engine Off (KOEO), Key On Engine
Running (KOER) and Continuous Memory DTCs. See QUICK TEST for self-test procedures. DTCs may be
set in PCM and/or Alternate Fuel Control Module (AFCM). Only Continuous Memory DTCs are available from
AFCM. DTCs may be cleared from memory after DTCs have been recorded or fault has been repaired. See
CLEARING CODES . If fault still exists after clearing DTCs, DTC will reset.

KOEO & KOER Diagnostic Trouble Codes

KOEO and KOER DTCS indicate faults exist at time of testing and may turn the Malfunction Indicator Light
(MIL) on. The MIL is located on instrument cluster and may be labeled SERVICE ENGINE SOON or CHECK
ENGINE. For additional information on KOEO and KOER DTCs, see DIAGNOSTIC TROUBLE CODES
under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.
If KOEO or KOER DTCs are retrieved during KOEO ON-DEMAND SELF-TEST or KOER ON-DEMAND
SELF-TEST, see DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - CNG,
FLEX-FUEL & GASOLINE article.

Continuous Memory Diagnostic Trouble Codes

Continuous Memory DTC are retrieved after performing KOER ON-DEMAND SELF-TEST. Unlike KOEO or

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - Bi-Fuel - Gasoline/LPG

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - Bi-Fuel - Gasoline/LPG

KOER self-tests, which can only be activated On-Demand, Continuous Memory self-test is always active. A
fault may or may not exist at time of checking for Continuous Memory DTCs. This self-test is helpful in
diagnosing intermittent faults.

After noting and/or repairing fault, clear DTCs from memory. See CLEARING CODES . Intermittent faults
may be caused by a sensor, connector or wiring-related problem. See INTERMITTENTS in TROUBLE
SHOOTING - NO CODES - BI-FUEL - GASOLINE/LPG article.

RETRIEVING DIAGNOSTIC TROUBLE CODES

DTCs are retrieved from EEC-V system through Data Link Connector (DLC), located below instrument panel,
right of steering wheel. See Fig. 1 . Self-diagnostic test procedures are for use with Rotunda Worldwide
Diagnostic System (WDS), New Generation Star (NGS) scan tool or equivalent. If a generic scan tool is used,
ensure scan tool is certified to OBD-II standard. A generic scan tool may not be capable of performing all
necessary test functions. To retrieve AFCM Continuous Memory DTCs, see AFCM CONTINUOUS
MEMORY SELF-TEST .

Fig. 1: Identifying Data Link Connector Terminals
Courtesy of FORD MOTOR CO.

READING DIAGNOSTIC TROUBLE CODES

NOTE:

Continuous Memory DTCs should be recorded when retrieved. These DTCs may
be used to identify intermittent faults that exist after all KOEO and KOER DTCs
have been repaired. Some Continuous Memory DTC faults may not be valid
after KOEO and KOER DTCs are serviced.

NOTE:

Retrieving DTC from PCM must be performed first. Alternate Fuel Control
Module (AFCM) Continuous Memory DTCs are retrieved second.

NOTE:

If self-test will not activate or TOOL COMMUNICATION ERROR is received, see

2003 Ford Pickup F150

2003 ENGINE PERFORMANCE Self-Diagnostics - Bi-Fuel - Gasoline/LPG