Ford F150 Pickup. Instruction - part 1509

Perform this test when instructed by QUICK TEST. This test is only intended to diagnose:  

z

Differential Pressure Feedback (DPF) EGR Sensor  

z

Faulty EGR Valve  

z

EGR Vacuum Regulator (VR) Solenoid  

z

Orifice Tube Assembly. See Fig. 239.  

z

DPFEGR Sensor Pressure Hoses  

z

Vacuum Lines  

z

Wiring Harness Circuits (DPFEGR, EVR, EVR PWR, SIG, SIG RTN & VREF)  

z

Faulty Powertrain Control Module (PCM)  

Fig. 239: Identifying DPFEGR System Components 
Courtesy of FORD MOTOR CO. 

 

2003 Ford Pickup F150 

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

  

Fig. 240: Identifying DPFEGR Sensor Wiring Harness Connector Terminals (Lightning) 
Courtesy of FORD MOTOR CO. 

Fig. 241: Identifying DPFEGR Sensor Wiring Harness Connector Terminals (Explorer & Mountaineer)

 

2003 Ford Pickup F150 

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

  

Courtesy of FORD MOTOR CO. 

Fig. 242: Identifying DPFEGR Sensor Wiring Harness Connector Terminals (All Others) 
Courtesy of FORD MOTOR CO. 

Testing 

1) For KOEO, KOER & Continuous Memory DTC P0405 & P1400: Determine Present DPFEGR 
PID Voltage 
DTC P0405 and P1400 indicates EGR MONITOR failed due to average voltage to PCM dropping below 
minimum calibrated limit of less than .2 volt. Possible causes for this fault are: 

z

DPFEGR Circuit Shorted To GND Or SIG RTN Circuit  

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Faulty DPFEGR Sensor  

z

VREF Circuit Shorted To GND Or SIG RTN Circuit  

z

Faulty PCM  

Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, 
access DPFEGR PID from PID/DATA MONITOR & RECORD menu. If DPFEGR PID voltage is less 
than .2 volt, fault is currently present. Go to next step. If voltage is .2 volt or more, fault is intermittent. 
Go to step 5). 

2) Attempt To Induce Opposite DPFEGR Sensor Voltage 
 
Turn ignition switch to OFF position. Disconnect DPFEGR sensor harness connector. See Fig. 240-Fig. 
242 . Turn ignition switch to ON position. Using scan tool, access DPFEGR PID from PID/DATA 
MONITOR & RECORD menu. If PID voltage is 4-6 volts, replace DPFEGR sensor. If PID voltage is not 
4-6 volts, go to next step. 

3) Check VREF & SIG RTN Circuits For Open To DPFEGR Sensor 

NOTE:

For additional testing information, see DIAGNOSTIC AIDS.

 

2003 Ford Pickup F150 

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

  

 
Using a DVOM, measure voltage between SIG RTN and VREF circuits at DPFEGR sensor harness 
connector. See Fig. 240-Fig. 242 . If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, go to 
TEST C, step 1). 

4) Check DPFEGR Circuit For Short To Ground & SIG RTN In Harness 
 
Disconnect scan tool from Data Link Connector (DLC). Turn ignition switch to OFF position. Disconnect 
PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. 
Using a DVOM, measure resistance between DPFEGR circuit, and SIG RTN circuit at PCM harness 
connector, and negative battery terminal. See PCM CONNECTOR IDENTIFICATION and Fig. 240-
Fig. 242 . If both resistance measurements are more than 10 k/ohms, replace PCM. If either resistance 
measurement is 10 k/ohms or less, repair short to ground or SIG RTN in DPFEGR circuit. 

5) Perform Wiggle Test On DPFEGR Sensor & Circuit While Monitoring DPFEGR PID For A 
Sudden Change 
 
Ensure ignition switch is in ON position. Using scan tool, access DPFEGR PID from PID/DATA 
MONITOR & RECORD menu. Observe DPFEGR PID voltage reading for change while tapping lightly 
on DPFEGR sensor, and shaking and bending DPFEGR sensor wiring harness and connector to simulate 
road shock. A sudden change in DPFEGR PID voltage reading indicates a fault. If fault is indicated, 
isolate and repair as necessary. If no fault is indicated, go to TEST Z, step 1). 

10) For KOEO, KOER & Continuous Memory DTC P0406 & P1401: Determine Present DPFEGR 
Sensor PID Voltage 
DTC P0406 and P1401 indicate EGR MONITOR failed due to average voltage to PCM exceeding 
maximum calibrated limit of 4.5 volts. Possible causes for this fault are: 

z

Open In DPFEGR Or SIG RTN circuit.  

z

VREF Or DPFEGR circuit shorted To PWR.  

z

Faulty DPFEGR sensor.  

z

Faulty PCM.  

Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, 
access DPFEGR PID from PID/DATA MONITOR & RECORD menu. If DPFEGR PID voltage is more 
than 4 volts, fault is currently present. Go to next step. If DPFEGR PID voltage is 4 volts or less, fault is 
intermittent. Go to step 19). 

11) Check DPFEGR Circuit For Short To PWR 
 
Turn ignition switch to OFF position. Disconnect DPFEGR sensor connector. Turn ignition switch to ON 

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.

 

2003 Ford Pickup F150 

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