Ford F150 Pickup. Instruction — part 1480

110) For Continuous Memory Only DTC P0125 & P0128: Check Engine Coolant Level
This DTC indicates ECT or CHT sensor has not achieved required engine operating temperature level
within a specified amount of time after starting engine. MIL will be illuminated with this DTC. Possible
causes of this fault are:

z

Insufficient Warm Up Time

z

Low Engine Coolant Level

z

Leaking Or Stuck Open Thermostat

z

Malfunctioning ECT Sensor

z

Malfunctioning CHT Sensor

Check coolant level and fill as necessary. If coolant level is okay, locate cooling system fault and repair
as necessary. Perform DRIVE CYCLES. Ensure OBD-II DRIVE CYCLE is performed to verify repair.

TEST DM: MANIFOLD ABSOLUTE PRESSURE SENSOR & THERMAL MANIFOLD ABSOLUTE
PRESSURE SENSOR

Diagnostic Aids

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

z

Wiring Harness Circuits (MAP SIG, SIG RTN & VREF)

z

Faulty TMAP Sensor

z

Faulty Powertrain Control Module (PCM)

VREF voltage should be 4-6 volts. BARO PID reading is in frequency/volts.

while engine is operating or hot. Cooling system is under pressure
and steam and/or hot coolant can come out forcefully when cap is
loosened slightly.

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.

2003 Ford Pickup F150

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

Fig. 195: Identifying MAP Sensor Harness Connector Terminals (Aviator, Crown Victoria, Grand
Marquis, LS, Marauder, Thunderbird & Town Car)
Courtesy of FORD MOTOR CO.

Fig. 196: Identifying TMAP Sensor Harness Connector Terminals (Mustang 4.6L SC)
Courtesy of FORD MOTOR CO.

2003 Ford Pickup F150

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

Fig. 197: Identifying MAP Sensor Harness Connector Terminals (Ranger 2.3L)
Courtesy of FORD MOTOR CO.

Testing

1) For KOEO & KOER Only DTC P0107 Or P0108: Check Voltage Between VREF & SIG RTN At
MAP/TMAP Sensor
DTC P0107 indicates TMAP sensor reference voltage fell below calibrated limit of .25 volt. DTC P0108
indicates TMAP sensor reference voltage exceeded calibrated limit of 5 volts. Possible causes for these
faults are:

z

VREF Circuit Open, Shorted To Ground Or VPWR

z

TMAP Signal Shorted To VPWR

z

Faulty TMAP Sensor

z

Faulty PCM

Turn ignition switch to OFF position. Disconnect MAP/TMAP sensor connector. Using a DVOM,
measure voltage between SIG RTN and VREF circuits at MAP/TMAP harness connector. See Fig. 195-
Fig. 197 . If voltage measurement is 4-6 volts, go to next step. If voltage measurement is not 4-6 volts, go
to TEST C, step 1).

2) Check MAP/TMAP Sensor Operation

Connect 2 jumper wires to complete VREF and SIG RTN circuits between MAP/TMAP sensor harness
connector and MAP/TMAP sensor connector. Start engine and allow to idle. Using a DVOM, measure
voltage on MAP circuit between MAP/TMAP sensor connector and chassis ground. Observe voltage
while rapidly increasing engine speed to 3000 RPM by depressing accelerator pedal and then releasing. If
voltage rapidly increases to more than 2 volts and then decreases to less than one volt, go to step 4). If

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

2003 Ford Pickup F150

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

voltage does not rapidly increase to more than 2 volts and then decrease to less than one volt, go to next
step.

3) Determine Sensor Replacement

If vehicle equipped with EGR System Module (ESM) type EGR, replace DPFE/MAP sensor. If vehicle is
not equipped with ESM type EGR, replace TMAP sensor.

4) Check MAP/TMAP Circuit For Short To VREF & SIG RTN In Harness

Turn ignition switch to OFF position. Disconnect PCM connector. Using a DVOM, measure resistance
between MAP/TMAP circuit and both VREF and SIG RTN circuits at MAP/TMAP sensor harness
connector. See Fig. 195-Fig. 197 If each resistance is more than 10 k/ohms, go to next step. If either
resistance is 10 k/ohms or less, repair short between circuits.

5) Check MAP/TMAP Sensor Circuit For Open In Harness

Ensure ignition switch is in OFF position and PCM is disconnected. Using a DVOM, measure resistance
of MAP circuit between PCM harness connector and MAP/TMAP sensor harness connector. If resistance
is less than 5 ohms, replace PCM. If resistance is 5 ohms or more, repair open in TMAP circuit.

6) Continuous Memory DTC P0107 & P0108: Check For Intermittent Circuits To MAP/TMAP
Sensor

Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition
switch to ON position. Using scan tool, access MAP V PID from PID/DATA MONITOR & RECORD
menu. Observe MAP V PID voltage for indication of fault while shaking and bending MAP/TMAP
sensor wiring harness and connector. Tap lightly on MAP/TMAP sensor to simulate road shock. An
indication of fault is a sudden change in MAP V PID voltage. If a fault is indicated, isolate and repair as
necessary. If no fault is indicated, fault is unable to be duplicated at this time. Go to TEST Z, step 1).

TEST DP: VEHICLE SPEED SENSOR/TRANSFER CASE SPEED SENSOR

Diagnostic Aids

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

z

Vehicle Speed Sensor (VSS)

z

Transfer Case Speed Sensor (TCSS)

z

VSS Wiring Harness Circuits (VSS+ & VSS-)

NOTE:

After each service or repair procedure has been completed, reconnect all
components. Clear DTCs and perform DRIVE CYCLES. Ensure OBD-II DRIVE
CYCLE is performed to verify repair. After drive cycle is complete, repeat
QUICK TEST procedures to ensure all EEC-V systems are working properly and
DTCs are no longer present.

2003 Ford Pickup F150

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