Car shows "limp mode" or "reduced acceleration" warnings (possible ECU issue)

[Bulls-Vivid-Red]

April 24 build car, I've had it since June and zero issues outside of some paint defects. Well unfortunately today I'm joining the "Engine reduced acceleration" club. No error codes or check engine lights, just a pop up warning followed by the redline reduction. It was 95 degrees in Chicago today and I was in terrible traffic for well over an hour (AC cranking of course), hopefully just a case of things getting too hot?

I'll keep people posted if this was a one time deal or if it continues to pop up.

 

[Hell4Leather]

April 24 build car, I've had it since June and zero issues outside of some paint defects. Well unfortunately today I'm joining the "Engine reduced acceleration" club. No error codes or check engine lights, just a pop up warning followed by the redline reduction. It was 95 degrees in Chicago today and I was in terrible traffic for well over an hour (AC cranking of course), hopefully just a case of things getting too hot?

I'll keep people posted if this was a one time deal or if it continues to pop up.

That 200 degree coolant does seem hot but not too hot to flag a warning.

 

[kitkat]

200F is 100% normal, thats the target temperature to cool to on the Emira.

Engine reduced acceleration would be unrelated to this.

 

[trackday14]

That 200 degree coolant does seem hot but not too hot to flag a warning.

200°F coolant is the norm on a hot day - without traffic.

When this happened to me 2 weeks after my car was delivered (3/4/24), it went away - but came on again with a CEL and turned out to be the Mass Airflow Sensor.

 

[Hell4Leather]

200°F coolant is the norm on a hot day - without traffic.

When this happened to me 2 weeks after my car was delivered (3/4/24), it went away - but came on again with a CEL and turned out to be the Mass Airflow Sensor.

Those should be easy enough to get to. Did your dealer say anything about it afterwards?

 

[trackday14]

Those should be easy enough to get to. Did your dealer say anything about it afterwards?

It actually took 2 weeks for Lotus of Glenview (just north of Chicago) to diagnose the CEL code (Lotus Engineering had to be consulted to decipher the code), then a week to get the replacement part and make the fix.

 

[Bulls-Vivid-Red]

April 24 build car, I've had it since June and zero issues outside of some paint defects. Well unfortunately today I'm joining the "Engine reduced acceleration" club. No error codes or check engine lights, just a pop up warning followed by the redline reduction. It was 95 degrees in Chicago today and I was in terrible traffic for well over an hour (AC cranking of course), hopefully just a case of things getting too hot?

I'll keep people posted if this was a one time deal or if it continues to pop up.

Well good news I suppose in that I've now driven the car two more times since the reduced acceleration event and everything has been normal. It of course begs the question WTF happened......

 

[Hell4Leather]

It actually took 2 weeks for Lotus of Glenview (just north of Chicago) to diagnose the CEL code (Lotus Engineering had to be consulted to decipher the code), then a week to get the replacement part and make the fix.

The replacement part needing a week to ship I understand. Why on Earth would it take Lotus engineering two weeks to read a MAF sensor code? That’s pretty basic.

 

[trackday14]

The replacement part needing a week to ship I understand. Why on Earth would it take Lotus engineering two weeks to read a MAF sensor code? That’s pretty basic.

Apparently, at the time, the codes were not corresponding to clearly diagnosable issues…So Lotus Engineering had to decipher the code. It took 2 weeks for Lotus Engineering to respond to my dealership. It was ridiculous.

 

[Hell4Leather]

prob thought sporty exhaust crackles = speeding?).

What exhaust do you have?

 

[seriously]

sorry, its the stock one, but in sport mode, haha! still crackles and pops, though its not as loud/full bodied as I like sound wise.

i do want to do a 3rd cat delete but need to see if CA smog will still pass it, but that's another topic.

CA smog doesn’t need to know about it.

 

[seriously]

Wow for a low production car like an Elise! Yikes.

If it passes the sniffer I feel like I’m doing my part and the rest is just CA being stupid.

 

[Jjrho]

sorry, its the stock one, but in sport mode, haha! still crackles and pops, though its not as loud/full bodied as I like sound wise.

i do want to do a 3rd cat delete but need to see if CA smog will still pass it, but that's another topic.

no issues with taking 3rd cat out....it is not metered...i took mine off; sounds a bit better for sure...

 

[DJFirstEdition]

Received “Engine Reduction Acceleration” and was limited to 4000 RPM after a 2 1/2 hour drive at freeway speeds (65-80 MPH), but only after I got after the freeway.

No check engine light.

Got the car home in this limp mode (was only a few miles at that point).

Turned the car off to unload. Was only off for 5 minutes.

Started the car again to park in the garage.

Back to normal RPM limits.

I did buy a Bluetooth OBD reader, I should try and plug it in.

No idea.

(Ps - have not read through entire thread in case this is covered but will asap)

 

[seriously]

Received “Engine Reduction Acceleration” and was limited to 4000 RPM after a 2 1/2 hour drive at freeway speeds (65-80 MPH), but only after I got after the freeway.

No check engine light.

Got the car home in this limp mode (was only a few miles at that point).

Turned the car off to unload. Was only off for 5 minutes.

Started the car again to park in the garage.

Back to normal RPM limits.

I did buy a Bluetooth OBD reader, I should try and plug it in.

No idea.

(Ps - have not read through entire thread in case this is covered but will asap)

That’s strange. What mods- just 3rd cat delete?

 

[DJFirstEdition]

That’s strange. What mods- just 3rd cat delete?

Milltech exhaust in position one the entire time. Nothing else.

Edit:
I was able to scan with the Veepeak Bluetooth scan tool. This is what came up. I have not researched this code here yet. I thought I would post straight away before the day gets busy. I am unsure if I am reading this right because this is my first time using an OBD-II scanner.

"Distance traveled since DTC cleared is 796.6 miles." That would have been well before I owned the car, which now has 848 miles, the last several hundred of which are mine.

The part where I did not get a CEL "Engine Malfunction," but I did go into limp mode, didn't make sense re-reading my own post, so I thought I was gaslighting myself, but this says the same thing.

It would have been about 5 miles from when I went into limp mode and turned the car off if the CEL was on.

Disclaimers. I am just a guy who loves this car and is trying to learn about this stuff. My terminology or understanding of what I am looking at has a high chance of being inaccurate.

 

[DJFirstEdition]

Did the same route where I got this error. LA to LA Quinta and back again on the same day.

No issues. No limp mode. Similar ambient temps. It was a similar driving style, but maybe less aggressive

April 24 build car, I've had it since June and zero issues outside of some paint defects. Well unfortunately today I'm joining the "Engine reduced acceleration" club. No error codes or check engine lights, just a pop up warning followed by the redline reduction. It was 95 degrees in Chicago today and I was in terrible traffic for well over an hour (AC cranking of course), hopefully just a case of things getting too hot?

I'll keep people posted if this was a one time deal or if it continues to pop up.

Do you have an OBD-II reader, and if so, can you plug it in? Since the same thing happened (no CEL) but a limp mode, I am curious if we have the same reported error code.

I apologize for digging up the past here. I found your post, which is precisely what happened to me, and I read through it and realized you and I are asking the same question, "WTF happened?" and I haven't seen an answer anywhere yet.

 

[blueEmira]

Hey guys, have had an Emira for about a month and CEL with limp mode. Dealership says there are 7 codes, which they think is a "communication issue". They have had it for almost 2 weeks, and still haven't been able to diagnose with Lotus HQ. The car is obviously under warranty, but I am concerned that due to my driving habits, they might try to null the warranty (I took the car to 180 mph about 3000 miles in). During the break in period of 1000 miles I drove very timid, below 4000 RPM never full throttle. Is nulling the warranty a serious possibility? Thanks

 

[scc.131.fe]

Did you read anywhere in the vehicle's warranty text that driving at the speed which Lotus advertises will affect the warranty?

Also, would be a good idea to get all 7 codes in writing from your dealer.

 

[Rupes]

Hey guys, have had an Emira for about a month and CEL with limp mode. Dealership says there are 7 codes, which they think is a "communication issue". They have had it for almost 2 weeks, and still haven't been able to diagnose with Lotus HQ. The car is obviously under warranty, but I am concerned that due to my driving habits, they might try to null the warranty (I took the car to 180 mph about 3000 miles in). During the break in period of 1000 miles I drove very timid, below 4000 RPM never full throttle. Is nulling the warranty a serious possibility? Thanks

If driving your car fast after break in nulls your warranty, get a good lawyer. In fact, just get a bad lawyer, because you might as well save a few bucks on this very easy case to win.