2019 Defender XT Cab HD10 ECM Monster FI reflash

[Andystoy19]

I was bored a couple of weeks ago at -30C and realized that this was probably a slow time in the reflash business so I decided to remove the ECM and send it away for a reflash.

The ECM sits in a pocket behind the starter solenoid in the battery compartment and is difficult to see until you remove some parts in front of it. First remove the battery cover below the passenger seat in the cab.

Remove the negative and positive leads from the battery and I decided to remove the bracket (2 bolts) in front of the battery and the bracket on top of the battery to make more room to get at the wiring. Take the battery out and now you can see the 2-32 pin plugs that plug into the ECM which is in a pocket parallel to the back of the compartment. Cut the plastic wire tie next to the ECM at the top, remove the silver hex head screw that is on the far left and halfway down(left of the starter solenoid), it is the only screw holding the ECM in place. I removed the second silver hex head which holds the starter solenoid to the back so that I could move the wiring out of the way. I put an electric heater into the cab to warm up the wiring etc so that I wouldn't get any brittle insulation failures.

STOP and take a picture or visualize where the two cables are routed and which goes to the bottom plug "A" and where the second one goes to "B". My ECM had a blue marker across the connector and pin on A so that gave me a reference which cable went to A. They do not interchange and you don't want to damage the pins by forcing anything. Carefully move the clip on B up and back and this releases the connector, carefully wiggle the cable free and move it to the side. Cable A has the same clip so move it up and back and remove the connector and set it aside. The ECM can now be removed by holding the wiring and cables out of the way and jiggling the ECM as you pull to your right. Note that the flat side of the ECM is towards the front and the heat sink is on the back side where it exposed to cooling air. Note also that the ECM has a screw hole in the center left that protrudes into the cab and is held in place by the single silver hex head screw.

Place the ECM in a small well protected box and ship to Monster FI (or tuner of choice) along with the data sheet that he has on his website for you to fill out and enclose. Shipping time by Canada Post 4-5 days with tracking, one day turnaround and 4-5 days for the return.

To install the ECM first place it back in the pocket at the back and secure it in place with the silver hex head screw, install cable A at the bottom and carefully close the clip which moves the connector into place and locks it, so the same for cable B. Install the starter solenoid in place on the bracket with the other silver hex head screw. Loosely put in a new plastic tie wrap to replace the one you cut, install the battery top and front bracket. Install the positive and negative battery connections and pull the cable tie tight once you move the wiring back where it won't chafe on anything. Replace the battery cover and your done. Put the key in the  ignition and start, it runs and no check engine lights or alarms. Next will be a clutch kit towards Spring.

My Defender doesn't get used much in the winter because I have several sleds but I will get it out in March to further evaluate the tune and do some clutching, stay tuned.

The monster flash cost $400 CDN. $350US and he has a US contact for our friends south of the border. There are way too many options to list that Steve can change to make the engine more responsive: timing for fuel, rev limiter, engine fan temperature etc. I filled in the data sheet with a minimum of info and let Steve do his thing based on his experience, so in summary I have a 91 Octane no methanol tune for 2000' and up elevation, I am not planning on any further engine mods such as air intake, exhaust or engine work. I would best describe the tune as increasing the area under the curve from off idle to 9000 RPM, not that I would expect to see 8000 RPM once I do my clutch work. I will try and clutch for about 7650 RPM so you can leave your Rev Limiter at 8000 RPM if you wish, the 9000 leaves you a bit of room if you need to stay on the power in"Low" in the steep and deep but for me that would be a rare occasion as I am not a dragster and hate getting wet and muddy.

Steve does reply to his requests for info so if your interested in getting more info drop him a line, I have no ties to Steve other than the quest for more performance.

In summary too much free time, too little money, retired but it had to be done.🤔 No pics as even the ones in the Canam shop maual don't show you anything recognizable.

[Dragoon]

Thanks for all the info! I'm curious in a tune as well. I'm anxious to hear your thoughts after you've gotten some good miles on it after the tune.

[JimmyJames]

Now that its May Andy, how about a review of the pros and cons that Monster Tune?

[Hkb82]

I’m interested to hear the results also. 

[Andystoy19]

I have about 3 hrs. on the tune now, some in the snow and now out on the road. I didn't do as much bench marking as I would have liked before I decided to get the reflash in February so much of the update is about how the machine feels (subjective) as opposed to an objective test such as quicker by x number of secs. from 0-50 mph. This tune is for 91 Octane no methanol fuel and 2000' and up in elevation.

The engine starts and idles like a stocker, it has not displayed any check engine lights, faults or codes. Before the reflash if I went to WOT at 2500 RPM the engine would pull up to about 4600 RPM and than climb to about 6000 RPM on top end gradually. Now if you go to WOT throttle at 2500 RPM the engine goes to about 6100 RPM and the clutches have to do the work from there. The reason I use 2500 RPM is to reduce belt slippage in the primary when the belt has the least contact area. The machine has picked up some top end, maybe +/_ 5 mph although I haven't been back to the area where I first ran the stocker at about 50 mph indicated (55 mph corrected) and 6000 RPM. I have seen about 86 kph(54mph) at 6100 RPM on the speedo, corrected speed would be 60 mph.

The engine is very responsive from part throttle to WOT it runs smoothly and it would be hard to tell it has been tuned. Some of the things that changed are the reverse speed limiter has been raised so you no longer get the factory stutter, the rad fan has been programmed to come on sooner and cycle around 175F (the heater still puts out plenty of heat), the torque limiting programming has been changed, the rev limiter has been increased above the factory set 8000 RPM to allow some over rev in low range when you are to the pin, as well as the fuel and ignition tables. All in about 40 parameters have been changed but most of them are proprietary so if you decide to go for the reflash you can ask Steve for more specifics.

The limiting factor now is the stock clutching which holds the engine RPM to about 6100 throughout the shift range. I will get around to doing a clutch kit eventually where I would like to get about 7600 RPM max RPM in hi range. (Max power is 7000 RPM in the manual with stock tune.) This will allow the engine to get to max power quickly allowing the machine to accelerate quicker and become more responsive throughout.

I had the machine out in March in about 2' of settled snow spring snow, I was amazed at what the machine could go through at WOT (low range @ 6100-6500 RPM) breaking trail I was able to move forward without hanging up although I did see some marks of the skid plate dragging. There were rooster tails of snow off the front wheels and the back ones as well, unfortunately I didn't get a picure since I was driving.

You can get additonal HP for the Defender with heads, cams, exhaust, turbo etc. and you can get a tune that will work with your changes.

Bottom line is I am pleased with the tune and would do it again. For more information go to the Monster FI website. I have no connections or interest in the company.🙂

[JimmyJames]

Thanks for the update Andy. As always, you provided much detail and it appreciated.