Ford F150 Pickup. Instruction — part 1467

Fig. 178: Identifying Engine Fuel Temperature Sensor Connector Terminals
Courtesy of FORD MOTOR CO.

Fig. 179: Identifying Fuel Rail Pressure Sensor Connector Terminals (Natural Gas Vehicles)
Courtesy of FORD MOTOR CO.

2003 Ford Pickup F150

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

Fig. 180: Identifying Fuel Rail Pressure Sensor Connector Terminals (Except Natural Gas Vehicles)
Courtesy of FORD MOTOR CO.

TEST DC: MASS AIRFLOW SENSOR

NOTE:

After each service or repair procedure has been completed, reconnect all
components. Clear DTCs and perform KEEP ALIVE RANDOM ACCESS
MEMORY RESET PROCEDURE under CLEARING CODES under SELF-
DIAGNOSTIC SYSTEM. Repeat QUICK TEST procedures to ensure all EEC-V

2003 Ford Pickup F150

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

Diagnostic Aids

Perform this test when directed by QUICK TEST. This test is intended to diagnose the following:

z

MAF Sensor

z

Wiring Harness Circuits (VPWR, PWR GND, MAF SIG & MAF RTN)

z

Powertrain Control Module (PCM)

To prevent replacement of good components, be aware the following non-EEC related areas may be cause of
concern:

z

Air Cleaner Element

z

Inlet Air Duct

z

Throttle Body

For DTC P0102, a MAF V PID (MAF PID) reading less than 0.23 volt in Continuous Memory, or KOEO and
KOER indicates a hard fault. For DTC P0103, a MAF V PID (MAF PID) reading less than 4.6 volts in
Continuous Memory, or KOEO and KOER indicates a hard fault. Refer to illustration for specifications. See
Fig. 185.

Testing

1) For KOER Only DTC P1101: Check For MAF Sensor Continuous Memory DTCs
DTC P1101, retrieved during KOER on-demand self-test, indicates MAF sensor voltage signal was not
0.46-2.44 volts during KOER on-demand self-test. Possible causes for this fault are:

z

Low Battery Charge

z

Contaminated Or Faulty MAF Sensor Or Connector

z

Open In PWR GND Circuit To MAF Sensor

z

Open In MAF RTN Circuit To MAF Sensor

z

Faulty PCM

Drive vehicle for 6-10 minutes and repeat KOER ON-DEMAND SELF-TEST, KOEO ON-DEMAND
SELF-TEST and CONTINUOUS MEMORY SELF-TEST . If no Continuous Memory DTCs are
present with KOER DTC P1101, turn ignition switch to OFF position and go to step 3). If any
Continuous Memory DTCs are present with KOER DTC P1101, proceed as follows:

systems are working properly and DTCs are no longer present.

NOTE:

If the following test steps fail to diagnose MAF sensor concern, compare MAF
sensor voltages with voltages in MASS AIRFLOW table in SENSOR OPERATING
RANGE CHARTS article.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

2003 Ford Pickup F150

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

z

For Continuous Memory DTC P0102, go to next step.

z

For Continuous Memory DTC P0103, go to step 20).

z

All other Continuous Memory DTCs, service DTCs as necessary. See DIAGNOSTIC TROUBLE
CODE DEFINITIONS.

2) For KOER & Continuous Memory Only DTC P0102: Check MAF Sensor Signal Low Input To
PCM
DTC P0102 indicates MAF signal (voltage) fell below the minimum calibrated limit during KOEO or
KOER Comprehensive Component Monitor (CCM). Possible causes for this fault are:

z

MAF Sensor Disconnected

z

MAF Circuit Open To PCM

z

VPWR Circuit Open To MAF Sensor

z

MAF RTN Circuit Open To PCM

z

MAF Circuit Shorted To Ground

z

Intake Air Leak (Near MAF Sensor)

z

Closed Throttle Indication

z

Faulty MAF Sensor Or Connector

z

Faulty PCM

Check for broken or loose air outlet tube clamps at throttle body and air cleaner assembly. Check for
holes and cracks in air outlet tube. Check for worn gaskets between MAF sensor and air cleaner. Repair
as necessary. Start engine and allow to idle. Check for KOER DTCs. If KOER DTC P0505 is present, go
to TEST KE, step 2). On A/T models, if engine stalls or cannot maintain idle speed, go to step 7). If
KOER DTC P0505 is not present and engine idles okay, raise engine speed to 1500 RPM for 5 seconds,
then allow to return to idle. Using scan tool, access MAF V PID from PID/DATA MONITOR &
RECORD menu. If MAF V PID voltage is less than .23 volt, go to step 4). If MAF V PID voltage is .23
volt or more, go to next step.

3) For KOEO Only DTC P1101: Check For MAF Sensor Signal Out Of Self-Test Range
DTC P1101, retrieved during KOEO on-demand self-test, indicates MAF sensor voltage signal was more
than 0.27 volts during KOEO on-demand self-test. Possible causes for this fault are:

z

Low Battery Charge

z

Contaminated Or Faulty MAF Sensor Or Connector

z

Open In PWR GND Circuit To MAF Sensor

z

Open In MAF RTN Circuit To MAF Sensor

z

Faulty PCM

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

DTC P1101 may be caused by low battery voltage or by a poorly ventilated
work area. Ensure vehicle is vented to outside atmosphere before
repeating QUICK TEST.

2003 Ford Pickup F150

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