AWD Malfunction Warning After Low Tire

[w102acd]

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!

[1004ron]

Welcome.

 

Use your OBDII dongle with the free app FORScan Lite and scan for codes.

[w102acd]

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

[Wubster100]

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

[Haz]

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 April 14 by Haz

[w102acd]

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.

[w102acd]

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?

[w102acd]

After I reset the AWD DTC, I started it back up and the same code came up.  However, it has not switched the indicator light on.  So it seems like it's going to come back after we drive it.

[1004ron]

9 minutes ago, w102acd said:

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

Depends on which Model/Year you have.

 

Please add your Model & Year to your profile signature - https://www.fordedgeforum.com/settings/signature/

[w102acd]

2019 Ford Edge ST Turbo 2.7L

[w102acd]

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).

[1004ron]

Read @Haz post above and note section "AWD Control And Fault Indicators".

 

That should give you an indication the coupling, which I'm guessing you refer to as "actuator".

[Haz]

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

 

 

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...

 

 

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

 

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

[w102acd]

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.

[Wubster100]

Normally, only the front wheels will receive power, unless the AWD system responds to slip between the front and rear axles, or if wheel slip is anticipated before it occurs.

Edited April 20 by Wubster100

[edgeidiot]

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? 

[w102acd]

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?

[w102acd]

Update: Dealer did the diagnostics and concluded that the PTU actuator is bad citing A3 (>10,000 ohms resistance).  They are going to change it out.  $750 with the $200 diagnostic.  I think the breakout is $200 for diagnostic, $250 for the part, and $300 for labor.  Never thrilled with bills like these, but was expecting worse.

 

In retrospect, I think I could have handled this and saved $400-500.  Calling it a win for now though.

 

I appreciate the information...to make me an informed customer.  The write up I got were not great so I asked questions about A3 and he had to go get the tech who did the work to confirm.  I was also expecting a actuator change to include a draining of the PTU, but I guess it bolts to the PTU housing and is not wet with fluid.  Not sure what the seal does?  Just keep crap out of it?

 

I'll update once we get it back for future reference.

[enigma-2]

Thought that the electric AWD  actuator was attached to the front of the rear differential. 

[1004ron]

1 minute ago, enigma-2 said:

Thought that the electric AWD  actuator was attached to the front of the rear differential. 

It changed on the later models - not sure at what year they moved to the PTU.

[omar302]

5 hours ago, enigma-2 said:

Thought that the electric AWD  actuator was attached to the front of the rear differential. 

 

5 hours ago, 1004ron said:

It changed on the later models - not sure at what year they moved to the PTU.

 

In 2019 they switched to the PTU with disconnect function, however the rear differential still has the actuator. So the driveshaft can be fully disconnected from both sides and then would stop spinning. 

 

@macbwt previously made a video of it in action:

 

 

[Haz]

The 2019 Edge Workshop Manual provides a useful description of those newly added PTU & RDU capabilities, and how each component reacts to operational heat...

 

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

 

Power Transfer Unit (PTU) Operation

The PTU has four (4) modes of operation: Connected, Connecting, Disconnected, and Disconnecting. Each mode is commanded by the AWD module. The power transfer unit contains a reversible DC motor and two hall effect position sensors. The motor moves the shift fork which connects or disconnects the dog clutch collar. power transfer unit position sensor A monitors the position of the actuator cam. power transfer unit position sensor B monitors the position of the shift fork. Some power transfer unit models are equipped with an oil temperature sensor.

 

Connected Mode

Connected mode is the default mode for the power transfer unit. The AWD module will command Connected mode at the beginning of each key cycle. In connected mode, the fork and dog clutch collar are positioned towards the RH side of the power transfer unit and the dog clutch is engaged. The driveshaft will then rotate at an overdrive ratio compared to the front axle shafts. Torque will be available at the RDU .

 

Connecting Mode

To connect the power transfer unit, the two halves of the Dog clutch must be within 40 RPM of each other. The AWD module calculates the speed differential based on transmission OSS , RDU Driveshaft Speed, and power transfer unit gear ratio. The actuator motor will energize and rotate the gear reduction drive and the actuator cam against the shift fork. When the dog clutch teeth line up, the cam pushes the shift fork into position and the clutch engages. It can take approximately 100 - 150ms for the dog clutch to engage after the command is sent.

 

Disconnected Mode

The AWD module will command disconnected mode based on vehicle conditions. The purpose of the disconnected mode is to reduce drag losses from spinning the driveshaft when conditions indicate AWD will probably not be needed in the near future. In disconnected mode, the fork and dog clutch collar are positioned towards the LH or transmission side of the power transfer unit. The dog clutch is disengaged.

 

Disconnecting Mode

To allow disengagement of the RDU , no torque is routed through the power transfer unit, with the dog clutch being disconnected during this mode. Depending on vehicle operating conditions, the AWD module may keep the power transfer unit engaged for the remainder of the key cycle. The AWD module will send a duty cycle command to the power transfer unit actuator motor to disengage the dog clutch.

 

RDU Operation

Power distribution clutch motor for RDU:

The RDU System consists of an open type differential with an electronically controlled clutch pack that varies the torque applied to the rear axle shafts. The system has the capability to vary the amount of torque to the rear axles by controlling the clutch engagement pressure.

 

Economy Mode: When the RDU clutch pack is not engaged, the open differential allows the rear axle system to operated as a freewheeling axle, with no torque being transmitted from the RDU to either rear axle. In this mode the vehicle will operate as a 2WD system.

 

Connect Mode: When the AWD module determines that the AWD system function may be needed, the clutch pack is engaged to a “kiss point” by the actuator, spinning the rear axles up to speed. Once the wheel speed reaches a certain threshold, the power transfer unit will be connected (via the Torque mode), with torque provided to the RDU .

 

Torque Mode: When the vehicle is in torque mode, the RDU clutch motor will receive angular position commands to provide a requested amount of drive torque from the drive shaft to the rear axles. The RDU controls receive a torque request in Nm, which is converted into a motor angular position request value. These incoming torque requests are updated every 10ms by the AWD module.

 

Heat Protection - Power Transfer Unit

During excessive use or when towing a trailer, the AWD system may implement a heat protection mode to protect the power transfer unit from damage. Using the input from power transfer unit temperature sensors, the AWD module performs calculations to determine the demand for use of the heat protection mode. The AWD system then reduces the commanded torque being applied by the RDU to the rear axles, and/or disconnects the power transfer unit dog clutch. Once the maximum temperature limit is reached, AWD mode only is commanded and the AWD temporarily disabled or AWD OFF message is displayed in the IPC .

 

Heat Protection - Rear Drive Unit (RDU)

During aggressive on road driving, the AWD system may implement a heat protection mode to protect the RDU clutch from damage due to overheating. On variants not fitted with power transfer unit or RDU temperature sensors, the AWD module performs calculations to determine the need for the heat protection mode. If the AWD system detects an overheat condition, it enters a locked mode. If the heat in the RDU continues to rise once in the locked mode, the AWD module disables the torque commands to RDU . This condition may be indicated by an AWD Temporarily Disabled message in the message center. To resume normal operation, stop the vehicle in a safe location and turn the engine off for at least 10 minutes. After the engine is restarted and the AWD system has adequately cooled down, the AWD Temporarily Disabled message turns off and normal AWD operation returns. In the event the engine is turned off during the stop, the AWD Temporarily Disabled message turns off when the system cools. Normal AWD operation returns once the message center displays AWD Restored.

 

Good luck!

 

Edited May 17 by Haz

[enigma-2]

If I read this correctly, the actuator is still on the RDU but they added an electric clutch to the end of the PTU. (Basically they can disconnect the driveshaft from turning.)

[w102acd]

Update:  Frustrated with the dealer.  They had the car for over a week with several different folks involved.  They first said what I wrote in my previous post, that everything checked out except for A3 (PTU actuator resistance).  After 5 days, I was told they got the subframe out, changed the actuator, but were struggling to get the subframe back in.

 

Two days later I called and spoke to a supervisor not about the service, but about it being over a week to do less than a day worth of work and that I couldn't get anybody to call me and give me updates.  She was very apologetic and gave the job to another service tech.  Then I was told the new tech re-did the inspections and found a corroded wire on the PTU actuator harness and that everything else checked out.  They fixed the wire and it was good to go.  For my trouble...no charge.

 

Definitely some shady busy going on here.  They first reported that they had the subframe out and the actuator changed.  Then the new tech said the subframe never came out after I asked about the required alignment after the subframe came out.

 

However, now I have a new issue...

Edited May 21 by w102acd

[w102acd]

Got the car back from the dealer and no warning lights.  However, now it has a "hesitation" going from third to fourth gear.  By hesitation, it's almost like the a clutch is slipping or something.  With normal acceleration, when it goes to shift, the RPMs will increase, the car will slow down, then it will grab and everything is fine after that.  I think it's third to fourth at about 35 mph.

 

It seems to be worse when its cool and gets better after driving for a little bit.  After driving for a while the problem seems to go completely away.

 

Clearly not going back to the dealer...at least not the same dealer as above.  Should I find a new general shop or a transmission shop?  Transmission fluid change?

 

As another note, the dealer did look at the tires and said one of them is considerably more worn than the other three.  I guess there is a known issue with tires have different wear.  I was planning to look into tires as soon as I got it back, but the transmission slipping has my attention.

 

Any help/insight into what the problem may be would be appreciated!