Ford F150 Pickup. Instruction — part 1487

Fig. 212: Identifying PSP Sensor Circuits & Connector Terminals
Courtesy of FORD MOTOR CO.

Testing

1) For KOER Only DTC P1550: Verify Operator Interaction
DTC P1550 indicates PSP sensor signal was less than minimum or was more than maximum calibrated
limit during KOER self-test. Possible causes for this fault are:

z

Faulty PSP Sensor

z

Faulty Powertrain Control Module (PCM)

Ensure steering wheel was turned at least 1/2 turn within 30 seconds of starting KOER on-demand self-
test. If steering wheel was turned during self-test, repair any symptoms with power steering system that
are present. If no power steering symptoms are present, go to next step. If steering wheel was not turned
during self-test, repeat QUICK TEST.

2) For KOEO & KOER Only DTCs P0552 & P0553, Or For KOEO Only DTC P1550: Check
Voltage Between VREF & SIG RTN At PSP Sensor
DTC P0552 indicates PSP sensor circuit is open or shorted to ground. DTC P0553 indicates PSP sensor
circuit is shorted to VPWR. DTC P1550 indicates PSP sensor signal was less than minimum or was more
than maximum calibrated limit during KOEO self-test. Possible causes for these faults are:

z

Faulty PSP Sensor

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

2003 Ford Pickup F150

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

z

SIG RTN Circuit Open Or Shorted

z

VREF Circuit Open Or Shorted

z

PSP Sensor Signal Circuit Open Or Shorted

z

Faulty Powertrain Control Module (PCM)

Turn ignition switch to OFF position. Disconnect PSP sensor connector. Inspect connector for loose,
damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Using a
DVOM, measure voltage between VREF and SIG RTN circuits at PSP sensor harness connector. See Fig.
212. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, go to TEST C, step 1).

3) Check PSP Sensor Operation

Turn ignition switch to OFF position. Connect jumper wire to complete VREF circuit between PSP
sensor connector and PSP sensor harness connector. See

Fig. 212

and Fig. 213 . Connect another jumper

wire to complete SIG RTN circuit between PSP sensor connector and PSP sensor harness connector. Start
engine and allow to idle. Using a DVOM, measure voltage between chassis ground and PSP circuit at
PSP sensor connector. See Fig. 213. Observe voltage while turning steering wheel at least 1/2 turn to the
right and to the left. If voltage is .3-4.7 volts and changes when steering wheel is turned, go to next step.
If voltage is not .3-4.7 volts or does not change when steering wheel is turned, replace PSP sensor.

2003 Ford Pickup F150

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

Fig. 213: Testing PSP Sensor Operation
Courtesy of FORD MOTOR CO.

4) Check PSP Sensor Circuit For Open In Harness

Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose,
damaged or corroded terminals. Repair as necessary. Ensure PSP sensor is disconnected. Using a DVOM,
measure resistance of PSP circuit between PSP sensor harness connector and PCM harness connector.
See Fig. 212. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open
in PSP circuit.

5) Check PSP Circuit For Short To Power In Harness

Turn ignition switch to ON position. Using a DVOM, measure voltage between chassis ground and PSP
circuit at PSP sensor harness connector. See Fig. 212. If voltage is less than one volt, go to next step. If
voltage is one volt or more, repair short to PWR in PSP circuit.

6) Check PSP Circuit For Short To VREF, SIG RTN & Ground In Harness

Using a DVOM, measure resistance between PSP circuit, and VREF and SIG RTN circuits at PSP sensor
harness connector, and chassis ground. See Fig. 212. If all resistance measurements are more than 10
k/ohms, replace PCM. If any resistance measurement is 10 k/ohms or less, repair short in affected circuit.

10) For Continuous Memory Only DTCs P0552 & P0553: Check For Intermittent Circuits To PSP
Sensor
DTC P0552 indicates PSP sensor circuit is open or shorted to ground. DTC P0553 indicates PSP sensor
circuit is shorted to VPWR. Possible causes for these faults are:

z

Faulty PSP Sensor

z

SIG RTN Circuit Open Or Shorted

z

VREF Circuit Open Or Shorted

z

PSP Sensor Signal Circuit Open Or Shorted

z

Faulty Powertrain Control Module (PCM)

Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition
switch to ON position. Using scan tool, access PSP V PID from PID/DATA MONITOR & RECORD.
Observe PSP V PID voltage for indication of fault while shaking, wiggling and bending PSP, SIG RTN
and VREF circuits between PSP sensor and PCM. Tap lightly on PSP sensor to simulate road shock. An
indication of fault is a sudden change in PSP 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).

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 6) to step 10). No test procedures have been omitted.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

2003 Ford Pickup F150

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

TEST DU: INTAKE AIR TEMPERATURE 2

Diagnostic Aids

Perform this test only when directed here. This system test is intended to diagnose:

z

Intake Air Temperature 2 (IAT2) Sensor

z

Wiring Harness Circuits (IAT2 & SIG RTN)

z

Powertrain Control Module (PCM)

Fig. 214: Identifying IAT2 Sensor Circuits & Connector Terminals (F150 Lightning 5.4L SC)
Courtesy of FORD MOTOR CO.

See Fig. 196 for Mustang 4.6L SC.

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