Hey all, I own a 97 F-150 4X4 auto with 4.6 L .my problem is the check engine light on( code PO401) have checked the egr valve,tube back pressure and solenoid,but still get insuffecient flow code .any ideas? Also abs light on ,had code 9 and replaced speed sensor in axle.light still on,but has code 16 for all ok. anybodies help would be helpful.

 

The most common , by far, cause of a P0401 is a faulty DPFE sensor. Ford tells us now that if we see a P0401 to not check anything at all but just to replace the DPFE and clear the code. The call it "streamlined diagnostics" and it goes against everything we learn in their training courses but it's one more stupid way they are trying to save money. Ok, enough of that rant
The most common cause a LFC (light flash code) 16 is a blown Keep Alive Memory fuse for the ABS. Check all your fuses, under the dash and under the hood.

 

Thanks,I'll check it out.Did replace DPFE new in april and still have code after some driving.

 

Hey Luckild,
Dave is right about the DPFE. I would say 95% of what i see is this part failure. But there is nothing wrong with a little diagnostic work. If you put a mighty vac on the egr valve port, and apply some vacum, does the engine respond by slowing down, or stalling? if not you may need to take the throttle body off as well as the elbow that connects it to the intake and clean the egr flow ports. I just had one in the shop that was stopped up about 97%. Good luck

 

Thanks Boss, the port had a carbon ball in the port passage.did remove the plemiun and clear both holes. cleared and ok.any idea on the ABS light on, has code 16(all ok). later

 

This is out of the manual. The diagnostic connector they are talking about should be behind the passenger's kick panel.
One side of the connector will have the Bk/O wire, the other side should have a red wire.

Diagnostic Trouble Codes, Retrieving

CAUTION: Care must be taken to connect only the black/orange stripe wire to ground. Connecting the mating connector wire to ground will result in a blown fuse.

NOTE: Verify the ignition switch is in the RUN position (engine does not need to be running). Next, locate the black RABS II diagnostic connector. The diagnostic connector has two mating halves, one of which has a BK/O wire connected to it. Disconnect the two halves.

Attach one end of a jumper wire to the BK/O wire side of the diagnostic connector. Momentarily ground the opposite end of the jumper wire by connecting it to a ground for 1-2 seconds. Grounding this wire should start the yellow ABS warning indicator flashing. If grounding this wire does not start the yellow ABS warning indicator flashing, go to the Symptom Chart .

The code consists of a number of short flashes and ends with a long flash. Count the short flashes and include the following long flash in the count to obtain the code number. For example, three short flashes followed by one long flash indicates diagnostic trouble code 4. The code will continue to repeat itself until the key is turned off. It is recommended that the code be verified by reading it several times. This code will be used later for system repair instructions. It should be written down for future use. A diagnostic trouble code 16 is obtained when the anti-lock electronic control module detects normal system operation.


Diagnostic Trouble Codes, Erasing

The last step of the System Pre-Check always includes clearing the keep alive memory (KAM). Turn off the ignition while the diagnostic connector halves are separated as described in the procedures for retrieving the diagnostic trouble code. The diagnostic connector should be re-assembled to provide KAM power to the anti-lock electronic control module. If at this time a valid code has been obtained, go to the appropriate pinpoint test for that code.

 

I found the diag. conn. and have tried to get the code from the computer for the past week and it will not flash. Can you give me any other ideas? I have a 97 F150 4x2 4.6L. This particular 97 was actually purchased in Feb. 96, so I don't know if that makes a difference.
Thanks

 

Did you disconnect the diagnostic connector and then only ground the black with orange side?
Have you checked your fuses?

 

Yes, I only grounded the black/orange wire. I tried different grounds and different jumper wire. I have also replaced the rear sensor.

I pulled, I believe, #14 fuse and checked it. It looked fine. I noticed that when the fuse is out, the brake and ABS warning lights are on and do not go off when the ignition is turned on. I'm assuming this is normal operation.

 

I found the control module in the engine compartment. I disconnected one wiring harness that had about 16 female pins on it and reseated it. There was also another connection that had, I think a green/brown and red wire. I could not get that one off. Is this the ABS control module I am looking at? In any event, I am still getting the ABS light. Any other suggestions before I haul the thing into Ford?

 

Another trick - which probably won't help in this case, is to disconnect the battery, go have lunch, and come back. Reset the dash clock if you have one, and see if the problem still exists.

Rebooting does wonders - sometimes! It is the simplest tool I know, and does, on occasion even work.

Cactus Pair.

 

Hi, Racerguy. I know this is an old thread, but wanted to reference the procedures you outline above for checking for codes for the ABS. Would they pertain to my, what I think is my, RABS on my 94 E350 7.5L AT EEC-IV (mfd. end of '93, I believe)? And would the ABS ECM be behind the right kick panel. My CC doesn't work either-nothing; could that be related?

Ford told me it's the Anti-lock ECM (they called it ECU) causing the fault; said it would be $450. Had it in there for a tranny flush and filter. Ideally I'd like to pull the codes and confirm this. If that's it, where's the best auto supply to get this part? Ford? Any pointers on installing the replacement other than unplug/unscrew old and reverse for new?

Thanks a heap.

Paul

 

I cant remember the last time I worked on the ABS on a van but I think the procedures for checking it should be the same. I don't have a manual at home for it.
You might be able to find some info at Autozone.com in the Repair Info section.

 

Think they would have info. on what the codes mean? So far, I think I've only come across that "Code 9" has something to do with maybe a wiring fault (that you described in another thread), and "Code 16" means "pass," I think. I could probably search the web for the others, if necessary. Appreciate it.

If necessary, is it best to get the ABS ECU from Ford?

Paul

 

Yes they have a listing of what the codes mean.
I'm not sure if you could get the control module from anyone other than Ford or a used one.