Ford F150 Pickup. Manual — part 1495

10) For Continuous Memory Only DTC P1651: Check PSP Circuits For Intermittent
Continuous Memory DTC P1651 is set when PCM does not detect a change in PSP signal input when
PCM is detecting a calibratable number of speed transitions. Possible causes for these faults are:

z

Vehicle Towed With Engine Running

z

Power Steering Hydraulic Concern Repaired, But DTC Not Cleared

z

Faulty PSP Switch/Shorting Bar Damage

z

SIG RTN Circuit Open

z

PSP Circuit Open Or Shorted To SIG RTN

z

Faulty Powertrain Control Module (PCM)

Ensure scan tool is connected to Data Link Connector (DLC). Turn ignition switch to ON position. Using
scan tool, access PSP V PID from PID/DATA MONITOR & RECORD menu. While observing PSP V
PID, lightly tap on PSP switch and shake, wiggle and bend PSP, SIG RTN or GND circuits between PSP
sensor and PCM to simulate road shock. Disconnect PSP switch. Check PSP circuit for short to ground.
While observing PSP V PID, wiggle and bend PSP, SIG RTN or GND circuits between PSP sensor and
PCM. A fault is indicated by a sudden change of PSP V PID value. If fault is indicated, turn ignition
switch to OFF position, isolate area and repair as necessary. If no fault is indicated, turn ignition switch to
OFF position, reconnect PSP switch connector and go to TEST Z, step 1).

TEST H: FUEL CONTROL

Diagnostic Aids

Perform this test when instructed during QUICK TEST or if directed by other test procedures. Only use this test
to diagnose the following:

z

HO2S & Sensor Connection

z

Fuel Injector &/Or Fuel Injector Circuits

z

Vacuum Systems

z

Harness Circuits (HO2S, HO2S GND, INJ 1-10, VPWR & SIG RTN)

z

Powertrain Control Module (PCM)

NOTE:

A break in step numbering sequence occurs at this point. Procedure skips
from step 5) to step 10). No test procedures have been omitted.

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

NOTE:

Continuous Memory DTC P1651 can be set if vehicle is towed while engine
is running, or if a power steering hydraulic concern exists.

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

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

z

Ignition System

z

Faulty Evaporative Emission System

z

EGR &/Or PCV System

z

Air Intake System

z

Engine Oil Contamination

z

Fuel System

z

Exhaust System Leaks Or Restriction

z

Engine Cooling System

NOTE:

HO2S may be displayed on scan tool as O2S.

2003 Ford Pickup F150

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

Fig. 230: Locating HO2S (4-Cylinder)
Courtesy of FORD MOTOR CO.

2003 Ford Pickup F150

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

Fig. 231: Locating HO2S (V6 Or V8 With Dual Exhaust)
Courtesy of FORD MOTOR CO.

2003 Ford Pickup F150

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