Mechanics

WHAT DO I DO NEXT?

2001 Ford Taurus • 130,000 miles

I had car scanned it came up code P1401. I replaced the DPfe sensor. Didn't help. So I did egr valve still runs irratic. What do I do now?
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Annard
June 9, 2012.




10) DTC P1401: Check Present DPFEGR Sensor PID

This DTC indicates EGR MONITOR failed due to average voltage to PCM
exceeding the maximum calibrated limit. Possible causes for this fault are: a) Open In DPFEGR Circuit Or SIG RTN Circuit
b) VREF Circuit Shorted To PWR Circuit
c) Faulty DPFEGR Sensor
d) DPFEGR Circuit Shorted To VREF Or PWR Circuit
e) Faulty PCM

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

11) Check DPFEGR Circuit For Short To PWR

Turn ignition switch to OFF position. Disconnect DPFEGR sensor harness connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between chassis ground and DPFEGR sensor harness connector DPFEGR terminal. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, go to step
13).

12) Check DPFEGR Circuit For Short To PWR In Harness

Ensure ignition switch is turned to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Using a DVOM, measure voltage between negative battery terminal and PCM harness connector DPFEGR terminal. If voltage is more than 10.5 volts, repair short to PWR in DPFEGR circuit. If voltage is 10.5 volts or less, replace PCM.

13) Simulate Opposite DPFEGR Sensor Signal

Turn ignition switch to OFF position. Connect a jumper wire between DPFEGR sensor harness connector DPFEGR and SIG RTN terminals. Turn ignition switch to ON position. Using scan tool, select DPFEGR PID
from PID/DATA MONITOR & RECORD menu. If scan tool error occurs,
disconnect jumper wire and go to step 18). If DPFEGR PID voltage reading is.05 volt or more, disconnect jumper wire and go to step
16). If DPFEGR PID voltage reading is less than.05 volt, disconnect jumper wire and go to next step.

14) Check VREF Voltage To DPFEGR Sensor

Turn ignition switch to ON position. Using a DVOM, measure voltage between DPFEGR sensor harness connector SIG RTN and VREF terminals. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, go to TEST C, step 1).

15) Check DPFEGR Circuit For Short To VREF In Harness

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 PCM harness connector DPFEGR and VREF circuit terminals. If resistance is more than 10 k/ohms, replace DPFEGR sensor. If resistance is 10 k/ohms or less, repair short between DPFEGR and VREF circuits.

16) Check DPFEGR 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 DPFEGR sensor is disconnected. Using a DVOM, measure resistance of DPFEGR circuit between PCM harness connector and DPFEGR sensor harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in DPFEGR circuit.

17) Check SIG RTN Circuit For Open In Harness

Using a DVOM, measure resistance of SIG RTN circuit between PCM harness connector and DPFEGR sensor harness connector. If
resistance is less than 5 ohms, replace PCM. If resistance is 5 ohms or more, repair open in SIG RTN circuit.

18) Check DPFEGR Circuit For Short To VREF In Harness

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 PCM harness connector DPFEGR and VREF terminals. If resistance is more than 10 k/ohms, replace PCM. If resistance is 10 k/ohms or less, repair short between DPFEGR and VREF circuits.

19) Monitor DPFEGR PID & Perform Wiggle Test On DPFEGR Sensor &
Harness

Turn ignition switch to ON position. Using scan tool, select 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).

KHLow2008
Jun 9, 2012.


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