Problem With My New 2017 C-Max

[Rick369]

I picked up my new 2017 C-Max Hybrid Platinum on January 2, 2017. The C-Max had 5 miles on the odometer when I drove it off the dealer lot. Drove it home for a total of 30 miles. Everything seemed to work fine. Parked the C-Max and 2 hours later had to run a few errands. Noticed the outside temperature display was gradually going higher and higher as I drove. The outside temperature display was fluctuating between 70 - 120 degrees even though it was 38 degrees outside. The auto climate control was set at 72 degrees. When the outside temperature display reached 72 degrees the air conditioning kick in and no heat. Drove the C-Max about 10 miles and came home and shut it down. Let it sit for another 2 hours and took it for another drive hoping that it was a temporary glitch. Same thing happened but this time the outside temperature display would range between 70 - 90 degrees. The outside temperature at this time was 34 degrees.

 

Started the C-Max this morning and drove 10 miles to the grocery store. Outside temperature was 38 degrees and the outside temperature display read correctly and the auto climate control worked as it should. Was in the grocery store for 30 minutes. Started the C-Max for the drive home. Outside temperature display was gradually rising again and fluctuating between 70 - 90 degrees. The auto climate control was set a 74 degrees. When the outside temperature display reach 74 degrees the air conditioning kicked on and no heat.

 

Have an appointment on Wednesday to take the C-Max into the dealer. Really disappointing because the C-Max has less than 70 miles on it. Traded in a 2015 Explorer Limited for the C-Max. The Explorer had 22,500 and never had to go in for a warranty claim. Only in for oil changes every 6,000 miles.

[stolenmoment]

The external temp sensor is in the passenger side mirror, at least on earlier models, and there have been reports of rain and ice getting in there and screwing up the readings.

 

Get the dealer to blow it out with air, look for water inside, etc.

[scottwood2]

Seems to be repeatable which is good for the dealer to find the problem.   Any car can have issues.  Hope they fix it quickly and get you back on the road again enjoying your new car.  

 

Also congrats on the new car.   I still look forward to driving mine everyday after 2 years.   It is a great fun car. 

[Rick369]

Drop the C-Max off at 8:30 this morning. Got a call from the service advisor at 4:00 this afternoon. Said he had good news and not so good news. The good news was that the dealer technician duplicated the problem on a test drive. The outside temperature today was 8 degrees. The technician said the outside temperature display was registering 60 degrees. The not so good news is that the technician could not find any faults when he ran diagnostics. He has contacted Ford for the next steps that he should take. I mentioned to the service advisor what I have read on this forum about other members that have had this problem and what they had done to correct the problem. Now the waiting game. Will have see how long it takes the dealer to resolve this issue. I got a loaner vehicle that Ford is paying for. Unfortunately the only vehicle that they had available was a 2016 Expedition. What a gas hog. I could physically see the gas gauge going down as I was driving. Probably getting 10-12 mpg in this cold weather. Hope I don't have to drive it very long.

[SnowStorm]

An intermittent "floating" value sounds like an intermittent open circuit somewhere - probably a connector.  If Ford can't give specific advice, the dealer should check all connectors in the circuit visually, wiggle the wires to try and replicate the problem and then unplug/re-plug each connector.  It could be a faulty pin or bad wire to pin crimp.  Hope its fixed soon.

[AZgman]

Bring the gas hog back and demand a car similar to your C-max!

[Rick369]

Got a call from the service advisor at 1:00 pm today. The dealer technician got approval from Ford late this morning to start removing parts on the C-Max to try to locate and fix the problem. Don't know what that means and what the technician will be tearing apart and what parts he needs to remove. Brand new vehicle with less than 100 miles and already having to remove parts. Does anyone know what parts the technician will be removing? Where does the outside air temperature sensor tie into to provide the Sync 3 screen with the outside temperature? Is it the BCM, ECM, or ? Where are the main control modules located in the C-Max Hybrid?

[plus 3 golfer]

The Ambient Temp Sensor is located in the RH exterior mirror and wired via the Battery Junction Box (fuse / relay box under the hood) to the PCM connectors (under hood LH side).  The temp data from the PCM is transmitted via the CAN to other modules.  If I counted correctly, there are five connectors between the sensor and PCM.  Other than the connector at the sensor, the connectors have many, many wires in them as the wiring harness makes its way to the PCM. 

 

The sensor is a thermistor.  When temperature increases the resistance of the thermistor in the circuit decreases.  The sensor signal to the PCM is determined by the ratio of a fixed resistor in the sensor and the thermistor resistance in series in the circuit.  As the thermistor resistance drops, the voltage signal to the PCM decreases.  So, an intermittent open circuit or an intermittent short to ground of the signal circuit to the PCM could cause a high ambient temp as the signal voltage might drop to zero.  

 

If the dealer can't find an obvious issue with the sensor, wires or connectors, the wiring harness (or parts of it) may need replaced to fix the issue. Hopefully, the issue is the sensor / chaffing wires / bad connector before the wires become part of the huge wiring harness.

[Rick369]

Thanks Plus 3 Golfer for the detailed information. It is my understanding that the Ambient Temperature Sensor, which is located on the underside of the RH outside mirror, cannot be replaced on its own because it is integrated into the mirror. If the sensor is defective, the RH outside mirror must be replaced. Is that correct? The mirror is painted the same color as the rest of the C-Max, in my case it is White Gold. Does the dealer get a finished painted RH outside mirror from the factory or do they get a RH mirror that is prime painted only and the dealer's body shop has to finish paint the mirror in White Gold?

[plus 3 golfer]

It doesn't appear that the whole mirror needs replaced as the guts of the mirror appear to come apart to for example change the light in the mirror. 

 

Thanks Plus 3 Golfer for the detailed information. It is my understanding that the Ambient Temperature Sensor, which is located on the underside of the RH outside mirror, cannot be replaced on its own because it is integrated into the mirror. If the sensor is defective, the RH outside mirror must be replaced. Is that correct? The mirror is painted the same color as the rest of the C-Max, in my case it is White Gold. Does the dealer get a finished painted RH outside mirror from the factory or do they get a RH mirror that is prime painted only and the dealer's body shop has to finish paint the mirror in White Gold?

It's not clear from the service manual.  

 

However, it you look at fordparts.com, you may be correct.  The sensor is not shown as a part in the RH mirror assembly.  Also, there are parts such as the mirror glass, puddle lights, motor, painted cover etc that can be purchased / replaced separately.  But the main body (excluding the replaceable parts) likely holds the sensor and does not have a part number. So, it looks like there is one part number for the entire mirror assembly excluding the painted cover which is needed just to replace the sensor.

http://www.ebay.com/itm/NEW-OEM-RH-RIGHT-PASSENGER-SIDE-REAR-VIEW-POWER-DUAL-FOLD-MIRROR-2013-14-C-MAX-/281779310920?fits=Make%3AFord%7CModel%3AC-Max&hash=item419b5b1148:g:Y6kAAOSwtnpXip8s&vxp=mtr

 

[Rick369]

Dealer service advisor called at 3:00 this afternoon. Told me the technician could not find any frayed wires, bad connectors, bent connector pins, etc. The dealer got approval from Ford to replace the RH outside mirror which houses the Ambient Temperature Sensor. The mirror is suppose to arrive at the dealer next week Tuesday or Wednesday.

 

Based on the information you provided above Plus 3 Golfer, I assume the technician will be using my White Gold mirror painted cover. My 2017 C-Max Titanium has the Bliss with cross traffic alert option. I am not sure but model year 2017 may be the first year that this option was offered on the C-Max.

[Rick369]

Dealer service advisor called and said the C-Max was fixed and ready for pick up. Picked it up at 4:30 this afternoon. Inside temperature display working fine for now. Climate control working as should. Time will tell if problem has been permantly fixed.

 

Here is what the work order states. Total cost to Ford, $519.00 plus 8 days of car rental.

 

"104 verified customer concern. Checked oasis, checked for codes, no codes registered. Contact hotline to find ppt. Followed ppt fb in wsm. Had to remove right front door panel to gain access to connector 626 and had to remove right front wheel and wheel splash guard to gain access to pcm. Removed pcm cover. Followed ppt says I have a short to power. Contacted hotline and waiting for response. Retested, do not have a short to power. Suspect Ambient Air Temp Sensor which is part of right front mirror. Removed and replaced with new right front mirror. Reinstalled right front door trim panel and retested. Verified concern has been fixed."

[joshg678]

Glad it's fixed!

Can you post some photos of your 17, want to see the difference between 16 and 17. Mostly we know front end differences

[Rick369]

I'll take some pictures tomorrow. There were a few 16's on the dealers lot when I bought my 17. I test drove a 16 SE because the 17 Titanium I bought was on it's way from the factory. The dealer expected to receive my 17 any day. Well that turned out to be 10 days because of the Christmas and New Year holidays. The only differences I noticed between the 16 and 17 were the headlights and the driver/passenger seat heater switch location. The 17 head lights look much better. The driver/passenger seat heater switch was moved from the front center console location to where the rest of the climate control is located. I believe the 13 - 16 had the dial with 5 heat settings. The 17 is a switch you push with 3 heat settings. It is identical to what my 15 Explorer had. Also the wheel rims on the 17 Titanium are different from the 16 SEL. I like the 17 Titanium rims better than the 16 SEL rims.

Edited January 18, 2017 by Rick369

[jestevens]

So a bad sensor then?  That sort of makes sense I suppose.  Glad it is fixed, enjoy.

[joshg678]

Do they have a pocket or something in place of the old heat seat switch?

[Rick369]

Yes, there is a little pocket on the front right hand side of the center console area. It is small and I don't see much use for it other than putting some loose change in there.

[joshg678]

My wife's 13 escape had that and I kinda wish I had that now

[mike884]

stupid question... why would the outside temperature sensor have any bearing on the operation of the inside climate control?

 

It looks like the problem is fixed, but wouldn't the interior have its own sensor to monitor temperature for the auto setting?

[Louder North]

stupid question... why would the outside temperature sensor have any bearing on the operation of the inside climate control?

 

It looks like the problem is fixed, but wouldn't the interior have its own sensor to monitor temperature for the auto setting?

 

You're right; there must also be an interior temperature sensor. 

[plus 3 golfer]

stupid question... why would the outside temperature sensor have any bearing on the operation of the inside climate control?

 

It looks like the problem is fixed, but wouldn't the interior have its own sensor to monitor temperature for the auto setting?

 

As OP indicated there was no faults (DTCs) detected by the climate control software, So, if the set point cabin temperature is above the cabin temp sensor value and the outside ambient temp sensor shows outside is higher than the set point temp, the algorithm will use outside air to bring the cabin temp up to the set point.  Since the outside sensor was giving a faulty high reading, the cabin was not being heated.  Generally, if such software detects that the outside temp sensor reading is bad, the algorithm will use a backup sensor like perhaps the intake air temp reading in place of the ambient temp sensor and throw a DTC.

[Rick369]

stupid question... why would the outside temperature sensor have any bearing on the operation of the inside climate control?

 

It looks like the problem is fixed, but wouldn't the interior have its own sensor to monitor temperature for the auto setting?

I can't answer your question. All I know is when the outside temperature, that displays in the top portion of the Sync 3 screen, exceeded the temperature that the auto climate control was set at, the airconditioning kicked in. In my case the auto climate control was set at 72, the outside temperature ranged from 34F to 38F, yet the outside temperature display registered anywhere from 70F to 120F. When the dealer tech confirmed the condition, it was 8F outside, yet the outside temperature display registered 60F. I've had the C-Max back for 2 weeks since the passenger outside mirror was replaced. Outside temperature display is registering the correct outside temperature and the climate control is working as is should.

[plus 3 golfer]

AC will come as long as these conditions are met:

 

"The A/C demand message is sent from the SOBDMC over the HEV High Speed Controller Area Network (HS-CAN) to the ACCM . The ACCM engages the A/C electric compressor when all of the following conditions are met:

• The PCM does not detect excessively high or low refrigerant pressure from the A/C pressure transducer.
• The PCM does not detect an ambient air temperature below approximately 35.6 °F ( 2 °C).
• The BCM does not detect an evaporator discharge air temperature below approximately 35.6 °F ( 2 °C)."

So, with auto control on, the modules may allow AC to turn on to control cabin humidity because the ambient temperature is believed to be high.  This doesn't mean the AC compressor is running full out.  It is simply running to keep humidity down.  If you look at the My View screen that shows climate demand, you probably would have seen minimal demand.  

 

This happens all the time for me (AC turns on) even with "real" ambient temps around 55 - 65 F and set point at say 70 F.  So, most times I manually turn AC off.  As soon as you turn AC off, you can feel the rise in humidity in the car and one is more uncomfortable.  Yet the cabin temp. is unchanged.  Auto climate control is simply trying to keep one comfortable by lowering humidity. :)

 

What does surprise me is that evidently the algorithms make no checks as to sensor integrity like emissions systems do and switch to alternative data.  IIRC, for the emissions system, there is a check of intake air temp sensor reading against ambient temp sensor reading.

Edited January 25, 2017 by Plus 3 Golfer

[mike884]

Oh ok, well apparently the system is smarter than I give it credit for.

 

Something was obviously glitching somewhere, but I assumed it wouldn't even take the outdoor air into consideration. If you ask for heat... it sucks in whatever air is outside and warms/cools it to what you have it set at, based on an inside sensor and ramps the fan up/down as needed.

 

But hey learning something new!

Edited January 26, 2017 by mike884