Ambient temp resistor hack to get "Pure EV" mode

[Zuikkis]

Hi guys,

originally hinted by Anko in another topic, someone on Facebook had modified the ambient temperature sensor to prevent ICE from starting when using the heater. I'm not on FB so I couldn't read the original message, but I thought I'd experiment on my own.

I found the resistance curve of the temperature sensor, at 2000ohm it should give about +21C. I removed the original sensor and replaced with a 2k resistor. Sensor is easy to find behind the grille, and can be removed without tools.. It's very tight and there is not much room, but it is possible to remove without removing the bumper.

I have to say that this is the best mod ever. It works very well. No need to play with heater controls when starting the car, you can leave the heater at +20C and start normally, without ECO mode or anything. Today I drove 20km to work in +0C weather, started from cold garage without preheating.. ICE did not start during the trip, 0.0l total gas used. Electric heater is blowing at full power but ICE does not start.

I own a PHEVbox with ICEHeaterStop, but I haven't been using the ICEHeaterStop part because it's simply not working in cold weather. But this ambient temp resistor mod works, and is very easy to do and return back to stock if needed.

Apparently car's logic is, when ambient is +21C and heater set at +20C, there is no need to start ICE because ambient is higher! But then the heater really compares to car internal temperature, and sets the electric heater to full power until internal temperature is correct.

I protected the resistor with water resistant grease and a plastic bag. Would be better with a proper connector of course, I have to see if I can find one from aliexpress or ebay..

I made a youtube video, shows cold starting the car in +0C weather:
https://www.youtube.com/watch?v=Vy9ClGxiOh4

 

[littlescrote]

I hope for your sake that this sensor is not used for anything other than the HVAC, particularly the engine ECU as fooling that could cause engine damage.

 

[Zuikkis]

I hope for your sake that this sensor is not used for anything other than the HVAC, particularly the engine ECU as fooling that could cause engine damage.

Nah, engine has it's own sensors for intake air temp and engine coolant temp. Also drive battery has own sensor.

Simply unplugging this ambient sensor does not put up any warning lights or anything, only thing that happens is that the outside temp reading disappears from the dashboard. I'm sure the car would whine about it more if it was important..

Even if it somehow was connected to ECU, I doubt it could do any damage unless ambient temp is a lot HIGHER than the +21C it sees now. Lower air temperature is better for the engine.

I actually tune cars for living so I'm familiar with ECU's. I have never seen an ECU that uses outside temperature for anything. Intake air temp is often used, but it's measured in the intake manifold because air gets hotter when it passes through the hot engine room.

 

[ThudnBlundr]

The FB poster added a switch to the dashboard so that he could use the temperature sensor when required, but could bypass it through the resistor when he wanted.

 

[Zuikkis]

The FB poster added a switch to the dashboard so that he could use the temperature sensor when required, but could bypass it through the resistor when he wanted.

That would be nice. The mod is only needed in cold weather (under +10C or so). However, the only visible downside so far has been that dashboard thermometer always shows +21C now..

If I could find a suitable connector for the sensor, it would be very fast to change between fake and real sensor if needed.. It's really only a few minutes job to replace the sensor once you figure out how the locking is released.

 

[nils944]

This adresses a need (or at least a want) of many PHEV owners. Would be great to be able to buy a kit for such a mod, especially if it came with a bypass switch.

 

[Regulo]

This unwanted and unnecessary engine starting is something that has always niggled me, and if it's as easy as swapping a sensor that I can get to, I'd do it. One point, it will affect the "Icy road" warning at 3C, is there a problem there? I presume it just won't give that warning?

 

[Zuikkis]

This unwanted and unnecessary engine starting is something that has always niggled me, and if it's as easy as swapping a sensor that I can get to, I'd do it. One point, it will affect the "Icy road" warning at 3C, is there a problem there? I presume it just won't give that warning?

Yeah you are right, the 3C warning is gone. Also with the dashboard temperature showing +21C, there actually is a real risk of not realizing the roads are freezing.

Another thing I have noticed, it is now possible to start A/C cooling even if temperature is below zero. Originally it was not possible, the compressor would not start when it's that cold. This is not dangerous as it is, but after a while ice will start building up on the condenser and eventually even block it..

It's unlikely that anyone wants to use cooling if it's below 0C. But due to ingenious Mitsubishi design, cooling is always activated if you use windscreen defrost mode on the heater. You have to manually hit the snow flake button to disable cooling. So this is a possible mistake to make..

These are the only downsides so far I have noticed. Still, in my opinion the joy of pure EV drive outweighs small quirks like this.

 

[littlescrote]

This is not dangerous as it is, but after a while ice will start building up on the condenser and eventually even block it..

Evaporator, NOT condensor.

That is 'dangerous' for the A/C compressor as although the ice is 'only' blocking the airflow, it leads to too low pressure on the suction side of the compressor and too low flow of refrigerant and oil back to the compressor which can cause damage.

 

[Regulo]

Pics of where the ambient sensor connects to the ETACS box (from FB), in case anyone wants to try. I think I'll leave it alone. It's contacts 4 and 9 on connector C416, it's not that clear on the drawing.

 

[Regulo]

Pics of where the ambient sensor connects to the ETACS box (from FB), in case anyone wants to try. I think I'll leave it alone. It's contacts 4 and 9 on connector C416, it's not that clear on the drawing.

 

[acodo]

Very useful info here :

https://mitsubishitechinfo.com/data/GS41/2009/55/HTML/M155402020007701USA.htm

 

[ThudnBlundr]

Am I the only one who is slightly wary of someone posting a link to an unknown website (whatever the name) for their first post?

 

[PapaSierra]

Hi, I know the topic is 2 years old but there is so much useful information here that I cannot find elsewhere and I would really love to 'hack' my Outlander's temp sensor too. The problem is that none of the pictures you guys posted here are opening for me. I only see the jpeg file's name with a little picture icon but no actual picture. Is this a current technical problem with the forum or is it something on my side?

 

[littlescrote]

Hi, I know the topic is 2 years old but there is so much useful information here that I cannot find elsewhere and I would really love to 'hack' my Outlander's temp sensor too. The problem is that none of the pictures you guys posted here are opening for me. I only see the jpeg file's name with a little picture icon but no actual picture. Is this a current technical problem with the forum or is it something on my side?

Probably an issue with the photo hosting site. It's not working for me either.

 

[PapaSierra]

Ok, thanks for letting me know. I ended up replacing the sensor with a 3k3 resistor at the end of the cable but I prefer to locate the other end of these wires so that I can easily connect a resistor whenever the first cold days arrive and then disconnect it at the end of the winter.

My wife drove the card this morning with the resistor connected and OAT displayed on the dash as 10 degrees C (the actual OAT was around 3-4 deg). She was driving a distance of around 25km and actually forced the ICE to start by using the SAVE button as it was a very cold morning but she said that it took a very long time for the car to start getting any warmer inside and it never got properly warm so I will be taking the car myself tomorrow to see what's going on. I will report my findings. I definitely know that it behaves exactly as I wanted it to for any short distances like 5-10 minutes school runs or grocery shopping etc.

 

[vibes]

I tried on my Canadian 2018 Outlander GT PHEV with a 2K resistor and it didnt work. 21C reading on dashboard but ICE still starting bellow 7C.

 

[SilverD]

Hi guys, I dont live with the weather problems you have, but, I noticed on a topic on dbcam reset that mentioned the following site. This is a page that may or may not have an effect on your problem. https://carhoodsecrects.com/mitsubishi-outlander-phev-ev-mode-switch/

 

[kpetrov]

Do not work on my 2018 canadian model as well.
Finally I have installed a switch on engine main relay.