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AWD Malfunction Warning After Low Tire


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Hello all!

 

I have 2019 Edge ST with 124,000 miles that we just got from my in laws.

 

We went on vacation for a week and it sat.  We came home to a low driver side rear tire (25 psi) warning.  I put air in it and the low tire message went away, but immediately had the "AWD Malfunction Service Required" for the past week.

 

The car seems to be driving the same, but I can't get rid of the message.

 

I tried my OBD reader (cheap Amazon one) and no codes.  I tried unplugging the battery for ~15 minutes (positive only) and that didn't get rid of it.  I stopped by Autozone and they said their reader wouldn't be able to tell them anything either.

 

The only option left (that I can think of) is to take it to a dealer and have them look.  I'm not a fan of that because they always find things $2000-3000 in things that need repaired regardless of what I bring it in for.

 

It seems like the AWD message is related to the low tire message since they happened at the same time.  Is there a way for me to remove/reset the AWD message?  My intent would be to see if it comes back.

 

Anything else that I should check before taking it in?  Since it appears to be driving fine, should I be concerned about driving it?  The tires are also close to needing replaced and have read that might be the issue as well.  Do I really need to go to a dealer for this?

 

Thanks in advance!

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Thanks for the reply!

 

I have an el cheapo OBD2 scanner and don't get any codes:

https://www.amazon.com/ANCEL-AD310-Enhanced-Universal-Diagnostic/dp/B01G5EA74I/ref=sxin_17_pa_sp_search_thematic_sspa?content-id=amzn1.sym.b747a510-73a1-4cf4-a45b-74fc1ab8af95%3Aamzn1.sym.b747a510-73a1-4cf4-a45b-74fc1ab8af95&cv_ct_cx=obd2+dongle+forscan&hvadid=725841564141&hvdev=c&hvexpln=67&hvlocphy=9015812&hvnetw=g&hvocijid=17226922833890435540--&hvqmt=b&hvrand=17226922833890435540&hvtargid=kwd-2385225293896&hydadcr=6388_13390662&keywords=obd2+dongle+forscan&mcid=185d8463bea6309999e1499a76cc7e37&pd_rd_i=B01G5EA74I&pd_rd_r=49840cad-6cbc-4ec2-b1f1-d7de65722e4e&pd_rd_w=N31ds&pd_rd_wg=ma4kM&pf_rd_p=b747a510-73a1-4cf4-a45b-74fc1ab8af95&pf_rd_r=SP2MGEJ6TZYDQRWWNQ2E&qid=1744643548&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sr=1-1-6024b2a3-78e4-4fed-8fed-e1613be3bcce-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWM&psc=1

 

I'm completely open to buying a OBD2 dongle, but can you help me with what exactly to buy.  Just to confirm, this is a wireless device that plugs into the OBD2 port and I connect wirelessly to my iPhone?

 

Like this?:

https://www.amazon.com/TOPDON-Bluetooth-Diagnostic-Performance-Bidirectional/dp/B0C3QQYQ1B/ref=sr_1_22_sspa?dib=eyJ2IjoiMSJ9.oSZcGr4VWn2_jjxpg3u0MHdHiDsZNns4gwmmZxl-iAYqCBbVT-DOtbbi6s77uyIvzwU6_wAzNjA_Xv2EnxDHp-9L6AZc8m9ne-_5KP3aq57IjPB2HFGL7gRwfqwwHjpDNyfu3tcdj_lWoBdy5aNVWPX7wS2QKehooQecUyjhNgbt_rcTw4Kl6YOOqnns8W1IDMf2Xkn56gmUiVy5s1xWbYt32hbhveNzGeoLPb7sl8mYu54FwKxwPIKY4OzPVUnpIvqM4t3BLsNAdirnRveGmQbUk9AH7AYENMwFChuI99w.ePVmBlIWinRSNo7txHBQBtdu-c8aRRMArQkb9KdIesE&dib_tag=se&hvadid=725841564141&hvdev=c&hvexpln=67&hvlocphy=9015812&hvnetw=g&hvocijid=17226922833890435540--&hvqmt=b&hvrand=17226922833890435540&hvtargid=kwd-2385225293896&hydadcr=6388_13390662&keywords=obd2+dongle+forscan&mcid=185d8463bea6309999e1499a76cc7e37&qid=1744643548&sr=8-22-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9tdGY&psc=1

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Please see supported adapters at forscan.org. The most reliable way is to use a wired adapter with a Windows computer.

 

Supported adapters :

OBDLink EX USB, recommended USB adapter for Windows version of FORScan, also for configuration and programming functions

OBDLink MX+ BT, recommended Bluetooth adapter for Lite versions of FORScan (iOS, Android)

OBDLink SX/LX/MX

ELS27 (STN1170/2120)

ELM327-compatible (fully compatible with original ELM327, please also see important note below)

J2534 Pass-Thru

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Welcome to the Forum @w102acd!

 

From the 2019 Edge Workshop Manual, with emphasis added...

 

Placing your device cursor over underlined acronyms may yield popup full-words descriptions of the acronyms.

 

Spare Tire And Mismatched Tire Sizes

Major dissimilar tire sizes between the front and rear axles could cause the AWD system to stop functioning and default to FWD or damage the AWD system. It is recommended to reinstall a repaired or replaced road tire as soon as possible. When a mismatched or tire of the wrong size is fitted, an AWD OFF message may appear in the IPC . If this condition occurs, a DTC is set and an AWD OFF message is displayed on the message center. If there is an AWD malfunction service required message in the message center from using a spare or mismatched tire, this indicator should turn off after reinstalling a tire of the same size as the normal road tire, then cycling the ignition OFF and ON.

 

AWD Control And Fault Indicators

The AWD system consists of a Power Transfer Unit (PTU), driveshaft, front and rear halfshafts, AWD module, RDU with integral RDU coupling. The systems uses the AWD module for AWD control logic. Using inputs from various modules and systems, when the power transfer unit is engaged the AWD module sends a command to the RDU which controls the amount of torque applied to the to the rear wheels. AWD system faults are indicated by a driveline icon indicator in the IPC as well as the AWD malfunction service required message in the message center.

 

The following is Workshop Manual guidance on retrieving AWD-related Diagnostic Trouble Codes (DTCs)...

 

Inspection and Verification

NOTE: For most AWD System DTCs to set, the AWD module must detect the fault on 2 consecutive trips.

    • 1) Record and clear DTCs from the AWD module.
    • 2) Accelerate the vehicle from 0-45 mph with light (10%) APP.
    • 3) Maintain 45 mph for 10 seconds.
    • 4) Gently slow to a stop.
    • 5) Repeat steps 2-4.
    • 6) Accelerate the vehicle from 0-45 mph with moderate (30%) APP.
    • 7) Maintain 45 mph for 10 seconds.
    • 8) Gently slow to a stop.
    • 9) Repeat steps 6-8.
    • 10) Turn off ignition, wait 1 minute.
    • 11) Repeat steps 2-9 or until an AWD fault message is displayed in the IPC . Whichever is sooner.
    • 12) Retrieve continuous memory DTCs from the AWD module. If no DTCs are present, the concern may be intermittent. Do not perform a pinpoint test unless the concern is present.

 

Good luck!

 

Four-Wheel Drive Systems - Overview - 2019 Edge Workshop Manual.pdf Four-Wheel Drive Systems - System Operation and Component Description - 2019 Edge Workshop Manual.pdf

Edited by Haz
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Ordered the recommended USB adapter.

 

How do I "clear the DTCs from the AWD module"?  That's where I'm stuck at the moment.  I assume I need the USB adapter to do this?

 

We've continued to drive it without any issues.

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I received the recommended USB adapter, found the DTC, and reset it.

 

Here's the code and additional details.  I also attached a picture of the screen for even more details:

Code: C0090 - 4WD/AWD Power Transfer Unit Actuator

 

Additional Fault Symptom (:-18):

-Circuit Current Below Threshold

 

I'll do some additional research on this code.

 

Sounds like I need to replace the AWD Power Transfer Actuator.  How hard is that to do myself?

 

Is there any issue continuing to drive it until I get it fixed?

image.png

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I'm seeing lots of issues with the PTU regarding no drain plug, fluid changes, etc.  However, not a lot on the actuator itself.  Is the actuator in the PTU?  I'm guessing it is, so likely need a whole new PTU?

 

We've been driving it and (other than the AWD malfunction light) wouldn't notice anything wrong (no sounds/smells/etc).

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Our having the Diagnostic Trouble Code (DTC) enables us to gain fuller understanding from the 2019 Edge Workshop Manual...

 

image.png.a857028330c91c392aa2626528841fe0.png

 

So, the potential failure modes involve wiring and/or connectors, the PTU Actuator Motor, or the AWD Module.

 

The potentially involved wiring and/or connectors between the PTU Actuator Motor and the AWD Module are highlighted in yellow toward the bottom of the following Wiring Diagram...

 

AllWheelDrive(AWD)ModuletoPowerTransferUnit(PTU)-HIGHLIGHTEDWiringDiagram-2019Edge.thumb.jpg.6563e46f34c43e63298fbbaf69243242.jpg

 

The Workshop Manual recommends performing electrical diagnostic Pinpoint Test A in order to assess which of the three failure modes - wiring/connectors, or PTU Actuator Motor, or AWD Module -- is the cause of DTC C0090:18 being set in the AWD Module.

 

Attached below as PDF documents are Workshop Manual and Wiring Resource sections that can provide you fuller awareness of the potential work involved in addressing the diagnostic effort and the various repair procedures.

 

Ford's online parts-selling site shows the PTU Actuator Motor...

 

Link to this FordParts webpage

PTUActuatorMotor-TransferCaseMotor-FordParts_com.thumb.jpg.403adb13fe43717b98ffb61f592b23fd.jpg

 

It's worth noting that replacement of the PTU Actuator Motor/Transfer Case Motor involves dropping the vehicle's Front Subframe, which is a substantial task that must involve the right equipment to ensure personal safety, as detailed in the below-attached Workshop Manual procedures.

 

Ford's Service Labor Time Standard (SLTS) for removing and installing a PTU in a 2.7L EcoBoost Edge is 6.1 hours. Replacement of the PTU Actuator Motor might involve another hour of Labor. So, Labor will be the majority of the cost if you have the job done by a professional technician at a dealership or independent repair facility.

 

While you might undertake the electrical diagnostic procedure to personally assess wiring/connectors and the state of the PTU Actuator Motor, keep in mind that a professional technician will duplicate that task prior to replacing the PTU Actuator Motor, with the SLTS for that being 0.3-0.5 hour of Labor, which is less time than it would take me to put our 2015 MKX up in the air and safely roll underneath it.

 

Good luck!

 

All Wheel Drive (AWD) Module to Power Transfer Unit (PTU) - Wiring Diagram - 2019 Edge.pdf PTU Actuator Motor - Diagnostic Pinpoint Test ''A'' - 2019 Edge.pdf All Wheel Drive (AWD) Module - Connector C3841 Location - Under vehicle, right front floor pan area - 2019 Edge.pdf All Wheel Drive (AWD) Module - Connector C3841 Pinout Diagram showing Pin-Circuit Detail - 2019 Edge.pdf Power Transfer Unit (PTU) - Connector C1898C Location - Engine compartment, right hand side - 2.7L EcoBoost - 2019 Edge.pdf Power Transfer Unit (PTU) - Connector C1898C Pinout Diagram showing Pin-Circuit Detail - 2019 Edge.pdf All Wheel Drive (AWD) Module - Removal and Installation - 2019 Edge Workshop Manual.pdf Power Transfer Unit (PTU) - Actuator Motor Removal and Installation - 2019 Edge Workshop Manual.pdf Front Subframe - Removal and Installation - 2019 Edge Workshop Manual.pdf

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Thanks for all of the information!  Sounds like a trip to the shop is in order.

 

How urgently do I need to get it in?  It sounds like with the actuator motor stalled, the car is either stuck in AWD or FWD all the time.  If I switch to the AWD screen on the dash, it shows all 4 wheels as blue.  I'm guessing that means the PTU is stuck in AWD mode all the time?

 

Correct me if I'm wrong, but it doesn't sound like I need to stop driving it immediately and take it to the shop tomorrow.  My son drives it to school and home several times a day (maybe 50 miles a day and no more than 10 miles from home).  I have some work travel coming up week after next so will plan on getting it in then.

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Concerning the original TPMS warning, did you determine why one tire suddenly lost ten psi? I am trying to understand what could cause this. As little as a tiny leak in the tire or the wheel should have caused the tire to completely deflate in a week. If the valve stem was leaking, the TPMS occasionally should have measured that the pressure was low. Was it parked in an airport parking lot where someone depressed the value stem? What was the pressure for the other three? 

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No real explanation for the original TPMS warning.  It was parked in our garage while we were at Spring Break for the week.  Going from memory, it was 25 psi and the others were 35 psi.  I haven't checked them since, but haven't had the warning pop back up either and it's been a couple of weeks.

 

However, the PTU warning seems unrelated to the TPMS warning.  Or am I missing something?

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