Collision assist unavailable, check 4 x 4 , p0106, p06a7 ALL at the same time WTH ???????

[sootie007]

Still in the shop no diagnosis yet ...thanks so much for the advice above airline tech. Valuable info. I am an electronics technician myself for 40 yrs so I get it and have chased down lower than normal voltage references on analog busses, in equipment etc. What I am not sure of is what are the current codes displaying since they have had it . Ford engineering told them evidently there is a short, open or chaffe somewhere (pretty generic) and they need to find it. My logic would be rather than pulling the truck apart looking at the harness - instead measure the ref voltage , pull 1 sensor at a time out of the vref circuit until the voltage rises to its expected value. When it does you have found your culprit if its a bad sensor dragging the ref down instead of a wiring fault- again "IF" its a sensor. Im going to ask for specifics so I can possibly help - looking at wiring diagrams as you did .

Sponsored

 

[RangerBill]

Still in the shop no diagnosis yet ...thanks so much for the advice above airline tech. Valuable info. I am an electronics technician myself for 40 yrs so I get it and have chased down lower than normal voltage references on analog busses, in equipment etc. What I am not sure of is what are the current codes displaying since they have had it . Ford engineering told them evidently there is a short, open or chaffe somewhere (pretty generic) and they need to find it. My logic would be rather than pulling the truck apart looking at the harness - instead measure the ref voltage , pull 1 sensor at a time out of the vref circuit until the voltage rises to its expected value. When it does you have found your culprit if its a bad sensor dragging the ref down instead of a wiring fault- again "IF" its a sensor. Im going to ask for specifics so I can possibly help - looking at wiring diagrams as you did .

The DTC code P0106 could indicate a damaged MAP sensor, so it would seem logical to start with that one sensor first. If it is bad, it could cause the P06A7 vref faults. See attached file for descriptions of both codes. It could also indicate bad or shorted wiring to that sensor.

 

[RangerBill]

Still in the shop no diagnosis yet ...thanks so much for the advice above airline tech. Valuable info. I am an electronics technician myself for 40 yrs so I get it and have chased down lower than normal voltage references on analog busses, in equipment etc. What I am not sure of is what are the current codes displaying since they have had it . Ford engineering told them evidently there is a short, open or chaffe somewhere (pretty generic) and they need to find it. My logic would be rather than pulling the truck apart looking at the harness - instead measure the ref voltage , pull 1 sensor at a time out of the vref circuit until the voltage rises to its expected value. When it does you have found your culprit if its a bad sensor dragging the ref down instead of a wiring fault- again "IF" its a sensor. Im going to ask for specifics so I can possibly help - looking at wiring diagrams as you did .

Here is a list of sensors that use the vref power.

 

[airline tech]

I found the path for T-Shoot this noting: The VREF Circuit Ident = LE423
LE423 - Is fed from the PCM from 2 pins
C175B - Pin 13 - Feeds the AC Press Sensor & T-Case Motor
C175E - Pin 25 - Feeds the MAPT Sensor, Eng Oil Press Sensor, DPFE Sensor (Inline Connector C1019)
then to the Fuel Rail Press Sensor

So, by only using the codes and messages provided the T-Shoot is simplified down some and note that the VREF circuit is internally spliced in the PCM feeding the noted sensors on the circuit.
It is just a matter of isolating the circuit, with the T-Case Motor being exposed to weather might be a source for shorting the circuit.

There are multiple avenues to go about T-Shooting the circuit, Power Probe, Tone Tester or simple Ohm Meter

 

[Ohwell]

Still in the shop no diagnosis yet ...thanks so much for the advice above airline tech. Valuable info. I am an electronics technician myself for 40 yrs so I get it and have chased down lower than normal voltage references on analog busses, in equipment etc. What I am not sure of is what are the current codes displaying since they have had it . Ford engineering told them evidently there is a short, open or chaffe somewhere (pretty generic) and they need to find it. My logic would be rather than pulling the truck apart looking at the harness - instead measure the ref voltage , pull 1 sensor at a time out of the vref circuit until the voltage rises to its expected value. When it does you have found your culprit if its a bad sensor dragging the ref down instead of a wiring fault- again "IF" its a sensor. Im going to ask for specifics so I can possibly help - looking at wiring diagrams as you did .

Did you check all the battery connections, including the connection under the red boot on the firewall side of the under the hood fusebox? That is the connection that feeds the fusebox. To have that many faults, you need low voltage going to many circuits.

 

[sootie007]

Agree....thanks all....will let all know what I hear back.

 

[sootie007]

So 10 days in the shop - $270 for a rental car- they couldnt find anything concretely wrong after measuring voltages, shaking harnesses, scoping, looking for wire chaffes , wire breaks after talking with Ford engineering etc . So they reset the battery and codes ...I paid $232. I told them to drive it repeatedly 3 times. They said they did, including the shop foreman - 15 miles supposedly. All they could theorize is the ECU freaked out when the new battery was put in. 5 MINUTES driving out of the dealership my check engine light comes on. Disgusted I drove home. It drove ok on the way home regardless of the code. Put my reader on it at home and its 3 occurrences of code P139B (a new different code than before) . EGR-DPFE. VREF does go to the DPFE so I ordered a DPFE sensor off Amazon and will install it tomorrow and let everyone know what gives. So symptoms and codes to this point are

Collision assist unavailable
Check 4 x 4
Codes P0106. P06A7
Check engine light
Wrench light
drove horrible - missing cylinders, shift points jacked up
NEW battery installed, wouldnt run properly, drove to dealership
No start condition at dealership
Dealer looked for wiring issues 9-10 days - n.p.f.
Battery reset procedure
After dealership attempt at fixing -driving home now , P139B is displaying 3 times with a check engine light lit.

Currently we are at a check engine light with 3 occurances of P139B DPFE
" Code139BDefinition:EGR Sensor C Upstream Hose Off Or Plugged ".

The saga continues.

 

[RangerBill]

So 10 days in the shop - $270 for a rental car- they couldnt find anything concretely wrong after measuring voltages, shaking harnesses, scoping, looking for wire chaffes , wire breaks after talking with Ford engineering etc . So they reset the battery and codes ...I paid $232. I told them to drive it repeatedly 3 times. They said they did, including the shop foreman - 15 miles supposedly. All they could theorize is the ECU freaked out when the new battery was put in. 5 minutes out of the dealership my check engine light comes on. Disgusted I drove home. It drove ok on the way home regardless of the code. Put my reader on it at home and its 3 occurances of code P139B (a new different code than before) . EGR-DPFE. VREF does go to the DPFE according to Ranger Bills chart on post #18 above and airline techs post #19 above . SOOOO I ordered a DPFE sensor off amazon and will install it tomorrow and let everyone know what gives.

Gasoline Engines PCED
P139B - EGR Sensor C Upstream Hose Off Or Plugged

Description: ​	At idle, the exhaust gas recirculation (EGR) monitor commands the EGR valve closed and checks the differential pressure across the EGR tube orifice which should be zero to indicate the hoses are connected and not restricted. This DTC sets when the differential pressure indicated by the sensor exceeds a maximum threshold or falls below a minimum threshold.​
Possible Causes: ​	The upstream hose is disconnected The upstream hose is restricted Restricted or damaged EGR tube
Diagnostic Aids: ​	Look for signs of water or icing in the hose. Verify the hose connection and routing. Check the differential pressure feedback EGR sensor for correct mounting and function.​
Application ​	​	Key On Engine Off ​	Key On Engine Running ​	Continuous Memory ​
All​	​	GO to Pinpoint Test HE .​

 

[airline tech]

With you only getting a Map Sensor & DPFE Code (actual codes)
Then I suspect either the Map or DPFE is shorting the circuit (Internally Shorting)
or the Splice (S155) is bad.
If they performed a deep wire check - they should have found a bad splice.
If you find an excess amount of (moisture) in the DPFE that may be the issue.
Hopefully the DPFE will cure the issue but if it does not - I feel it's in that wire run of that splice.

 

[sootie007]

Amazon DPFE came today....I pipe cleaned out both egr tube ports and felt nothing. Installed the part which was 49.99 and came with the 2 hoses crimped on. Fired it up and got an additional code -something to the effect excessive egr opening and the other code p139b. Assumed because it was a brand new sensor it threw that code...SO I cleared both codes and took it for a drive and everything seemed normal. No check engine light. Fingers crossed for the next few days -code free hopefully.......I will let everyone know how it goes over the next week. Thanks for all the help .

 

[sootie007]

Calling it good - no codes or issues and its been 4 days ....Special thanks to Airline Tech, Ranger Bill and others for the wiring research / help.

Sponsored