performed to verify repair. If downstream hose connections are okay, go to next step.
61) Inspect Downstream Pressure Hose For Plugging
Check downstream hose for proper routing. Ensure downstream hose is not pinched and that hose routing
does not have low spots where water may collect, freeze and plug hose in colder climates. Repair or
replace hose as necessary. Perform DRIVE CYCLES. Ensure EGR MONITOR PROCEDURE is
performed to verify repair. If downstream hose is okay, go to next step.
62) Check Orifice Tube Assembly & DPFEGR Sensor
Inspect DPFEGR sensor downstream connection for plugging or damage. See Fig. 245. Inspect intake
manifold side pressure pick-up tube and orifice tube assembly for plugging, loose connection or damage.
Repair or replace DPFEGR sensor or orifice tube as necessary. Perform DRIVE CYCLES. Ensure EGR
MONITOR PROCEDURE is performed to verify repair. If no faults are found, go to next step.
63) Check DPFEGR Sensor Output By Applying Vacuum With Hand Pump
Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Disconnect
pressure hoses at DPFEGR sensor. Connect hand vacuum pump to downstream connection at DPFEGR
sensor (intake manifold side or smaller diameter port). See Fig. 239. Using scan tool, access DPFEGR
PID from PID/DATA MONITOR & RECORD menu. Read the following DPFEGR PID values with
ignition switch in ON position:
z
DO NOT apply vacuum to sensor. Record DPFEGR PID value. DPFEGR PID value should be .2-
1.3 volts.
z
Using vacuum pump, apply 8-9 in. Hg (27-30 kPa) for 5 seconds. DPFEGR PID value should
increase to more than 4 volts.
z
Quickly release vacuum. DPFEGR PID value should drop to less than 1.5 volts within 3 seconds of
releasing vacuum.
If any DPFEGR PID values are not as specified, replace DPFEGR sensor. If all DPFEGR PID values are
as specified, reconnect DPFEGR sensor. Unable to duplicate or identify fault at this time, go to TEST Z,
step 1).
70) For Continuous Memory Only DTC P0401: Perform KOER Self-Test
DTC P0401 indicates EGR MONITOR failed due to PCM detecting EGR flow is less than desired
minimum while driving. Possible causes for this fault are:
z
Vacuum Supply
NOTE:
Ensure DPFEGR pressure hose is the correct repair part and not a
substitute.
NOTE:
A break in step numbering sequence occurs at this point. Procedure skips
from step 63) to step 70). 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