DIY Mazda Mobile Start replaced by iDatastart

Hi, new to the forum and did a lot of searching on the Mazda Mobile Start (MSS) discontinuation and alternate solutions. I found a number of posts on various aftermarket remote starts but not a lot of tips on a DIY install. We have 2 x CX5’s, a 2017 and 2022. The 2017 had the MMS which has been discontinued and our dealer never offered a key fob remote start alternative so I elected to get the Apple Car Play (love it!).

I recently wanted to (re)add remote start and inquired at the Dealer if Mazda had a Mazda option. Nope, only 3rd party. So, I contracted Mazda directly, same question. Answer: no Mazda remote start retrofit whatsoever. Perhaps I was naively thinking that they had developed a solution post the MSS deactivation.

After a lot of web research I settled on using the iDataStart module. What follows is my experience on doing this myself to save some bucks. Hope it helps those considering (or already have) a used CX5 that they want to add remote start to.

Note: long post follows.

Some background first. The iDataStart module is capable of using the OEM key fob with the ‘Lock-Lock-Lock’ sequence, or you can add either a 1-way or 2-way aftermarket (AM) fob or you can add a device like Drone Mobile to use your cell phone (a service fee is required). Of note is that can initially use the OEM fob and if you want to add the AM Fob or Drone later, you can. It does require reconfiguring (re-flashing) the module. For me, since the 2017 is only a daily commute car and the parking lot is just outside and in view of the office, I tested the range of the OEM fob while inside and was convinced that it would work. And if turns out not to be the case, I will add one of the extended range fobs.

Here are the products I got from the good folks at Crutchfield for $250 with free shipping.
  • iDatastart CMHCXA0 (Module) at $180
  • iDatastart ADS-USB-ECO (flashing tool) at $0 (was included for free)
  • iDatastart ADS-THR-MA3 (T-Harness) at $70
So now comes the confusion, at least for me. While their instructions are pretty good, it still left me a little perplexed.

First off, there are 2 wiring diagrams and while they represent the same thing they are modeled differently. The T-Harness Diagram is the most useful as it shows which plugs from the T-Harness plug into the module and vehicle. The Hardware Diagram is the same with the wires of the T-Harness ‘exposed’. And the T-Harness diagram has a scissors cutting the wire symbol. This is to show that you are expected to cut the wire on the cars harness and connect it to the T-Harness. Now for the issue: there are also scissor symbols on the Hardware Diagram in other locations as well. Do I need to cut these? No. It is meant to show that the T-Harness itself has this ‘cut’ built in. OK, got that figured out now.

Another bewilderment was power to the module. There is a diagram of the module pinout (what all the plugs and pins are for). Very clear that the M1 plug pin 2 is for power. But no pinout for the M4 and M5 plugs which are the primary ones used. How is the device getting power? And since M1 is not used I was unsure if its male spades are ‘live’ and have a risk of shorting out. What I was able to determine is that M1 is the ‘high power’ option on this module and not active is this application. The power must come from the connections to the cars wiring harness. Moving on.

Of note is that installation with the T-Harness is straight forward. On the vehicle harness side, you unplug the correct connection, plug it into the T-Harness and then plug the T-Harness into the now empty slot you just removed the car plug from. Think of it this way: the T-Harness is like a bridge or splice into the exiting car’s wiring harness. And only 2 plugs are impacted which are directly below the steering column and accessed after removing the column’s lower plastic trim cover. Then the other end of T-Harness has 2 plugs that insert into the module. Simple enough but need to get thru the flashing / programing which does require installing, removing, and reinstalling the module.

It will be more complex if you desire for the horn, lights and hood pin features. Horn to sound when it starts (I assume), parking lights to come on while running (I assume) as well as provide error codes, and hood pin to disable remote start when open as a safety feature. And that leads me to my First Tip:

Post figuring out the T-Harness connections I decided to NOT do the horn, lights or hood. Idea is to validate the system works and then do the hard part. These are not needed for the module to work.

Programming is done in a total of 3 parts. There are lots of warnings about disconnecting the battery but here is where another round of confusion creeped in. Page 8 Step 5 of the instructions says “WARNING: Disconnect power last. Disconnect module from vehicle.” And for Step 7 is says “Connect power first. Connect module to vehicle.” Huh? This seems in direct conflict with the intro warning that says “The vehicle’s battery should be disconnected during the installation process. Any modules or control units disconnected during your install, should be reconnected before reconnecting the vehicle’s battery.”

I followed the steps 5 and 7 exactly as stated and the module did not accept the second programming phase. Fortunately, nothing fried and now for Tip 2: Disconnect the car battery (negative terminal) prior to plugging or unplugging the module into the T-Harness.

This also led to Tip 3: if it does not work the first time, start over from the very beginning. In other words, the module was accepting re-flashing as expected (recall can re-flash to add a Drone Mobile, etc.). When using the iDataStart “Weblink” to flash the 2nd or 3rd time select ‘new module’ and go from there. There is no apparent ‘reset’ or ‘erase’ button on the module. I was successful with the 2nd round and did a 3rd to set some of the advanced features I wanted to adjust.

Regarding the advanced features when flashing. If you do not go to that page, they will be at their default values. Two features I recommend paying attention to: time to run and valet mode. Run time is selectable in 15 min increments and I chose 30. The Valet mode deactivates the remote start feature for when it goes into the shop to preclude inadvertent remote starting. There is a long list of methods to choose from and idea is that the method both deactivates and reactivates it. A sort of pat your head, rub your belly and turn around three times sequence that would never be done otherwise. Make sure you write it down and put it in the glove box!

Now what was interesting on my vehicle was that even without the additional wiring of the horn / lights they seemed to work anyway. Let me explain. For the horn, regardless of the remote start, when clicking the lock on the fob for the 2nd or 3rd time the horn sounds. This is a feature of the car and is unchangeable (I know there is a setting for the beep ‘high, med, low and off’ but this is not about the horn). So was unsure what the horn hookup to the module accomplishes. And while my parking lights did NOT come on when running on the remote start, they did flash three times. Hmmm. Would they also flash an error code, like a door being opened? Sure, enough they did 3 + 10 error code which is no start due to door open. What about the hood? I know these cars have a sensor already in the latch so what it connected somehow? Sure enough popping the hood precluded a remote start and the parking lights flashed the correct error code. A call into their tech support was as mystified as I was. Recall this car had the MSS to start with so perhaps that somehow tied it in. Unsure. But it left me pondering if I need to do any of this extra wiring. After all, for the parking lights it requires cutting part of car's wiring harness and splicing in the module. If I sell the car, I can remove the module but then I have a broken connection on the parking lights. So, for now, no extra wiring. More to follow once I start using it.
I also have the iDataStart on my CX-5. But I caught it on sale at Best Buy with the 6,000 foot remotes for $299 installed.

And they do run this sale about 3 or 4 times a year.
Wow > that’s an awesome deal! Our local BB succumbed to the Amazon pressures. In fact, the entire mall has now turned into a giant AMZ distribution warehouse. The local remote start & audio place quoted me about $850 with an AM fob hence the reason for going DIY.
Called up Best buy twice for detail. If you have Fob, would you have to give it up? I heard someone mentioned once it was install, the oem Fob is dead. I wanted to make sure, since having it as backup / selling car one day.
Called up Best buy twice for detail. If you have Fob, would you have to give it up? I heard someone mentioned once it was install, the oem Fob is dead. I wanted to make sure, since having it as backup / selling car one day.
No, I still have my factory fob. It actually works with the iDataStart. Press Lock 3x and the car starts!

Now that said, the range is only whatever the range is from the factory. It's not 6000' like the iDataStart fobs are, nor is it two way.
I put the idatastart in my 20 cx-5 as well as the drone mobile module. So far everything is working great except for whatever reason it will not go into valet mode. I go through the whole process and the turn signals flash to show the vehicle has gone into valet mode but it still starts when I press lock 3x on the fob or in the drone mobile app. Any ideas?
Ty for the Fob update. That really pushed me on getting it.
Yep it works great, you can also make it so you press lock then unlock then lock again too. I was also able to get the hood switch for the Mazda OEM remote start module and install it in my vehicle for about $25. Much easier and cleaner than using the hood switch supplied with the idatastart.
OK, last question. So I enjoy the function of car auto locking when it sense I'm outside with the key. And refuse to lock ( via key) when I'm inside. Does that still happen?
Now that I don't know. My car doesn't have any of that stuff. I simply press the button.
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any stats regarding how much it drains the car battery?
does it have a breaker that stops draining car battery if it goes below certain voltage? (like dashcams with a parking mode)
I heard it was 2-3 weeks. Any longer remove the battery. I don't own one. I know with my usb dash cam it kills the battery in 8 days. When my wife is sick, I have to remember to unplug the DC to usb adaptor. Mess up so many times, I always carry those batteries jumper now.
Not much of an electrician, but that don't seems to help. Not like I can bypass a 2 Guage into small port. I have seen other device that you add to the actual circuit line.

This might work "Low voltage cut-off plug for 12V outlet". Car is my wife and she works most days. Not really an issue. We learn to live with it. I wish the cx 9 would have direct 12V access in the front like the cx 5.