Motor Fault – Consult Handbook

[zaktaylor]

Motor Fault – Consult Handbook. Yellow warning sign, which flashes up then goes away, multiple times. power restricted. only seems to happen when the external temp is above 10 degrees C. MG4 SE LR Jan 2023 (72). Only 26k ODO.

Symptoms:

• Dashboard shows “Motor Fault – Consult Handbook”
• Car goes into reduced torque mode
• Acceleration significantly reduced
• Regenerative braking also greatly reduced
• Vehicle still drives normally otherwise
• Cabin heating still works fine

Reset behaviour:
If I park the car, lock it, and return a few minutes later, the fault clears and full power returns.

Very consistent temperature pattern:

• Below 10 °C ambient: fault does not occur
• Around 11–14 °C ambient: fault consistently appears

Distance before fault:
When it does occur, it usually appears after 15–28 miles of driving.

Example from yesterday:

• 145 mile journey
• About 78 miles were torque limited
• Later in the evening when temperatures dropped, the issue disappeared completely

Driving style:
Normal driving – I haven’t seen any link with heavy acceleration.

 

[Porsche944]

Sounds like something is over heating? All the coolant bottles at the right level. No puddles underneath?

 

[Tight Git]

If you have recently purchased this car second hand be very careful about how you proceed!

An early member who will remain nameless (who was banned) had similar issues which were never resolved and rejected the car. If you go down this path you will need to make sure you do everything by the book.

Good luck!

 

[Chrisdriving]

Maybe worth asking an MG dealer service dept?

 

[zaktaylor]

If you have recently purchased this car second hand be very careful about how you proceed!

An early member who will remain nameless (who was banned) had similar issues which were never resolved and rejected the car. If you go down this path you will need to make sure you do everything by the book.

Good luck!

Saw this - I've done 3500 miles fault free to be fair. however, its not been over 10/11 degrees until the last week or so. Therefore, i guess the fault could have existed but not surfaced until now.

 

[zaktaylor]

Maybe worth asking an MG dealer service dept?

Of course - Its booked in tomorrow. Have all my service receipts and has been serviced in line with warranty. Already had software updated and another minor fault I cannot recall sorted under warranty at Eden Swindon. So warranty should cover this fault. Will Report back.

 

[zaktaylor]

Sounds like something is over heating? All the coolant bottles at the right level. No puddles underneath?

No Puddles. Coolant between Max and min. but your right, the car defo thinks something is overheating/ or cant read temps correctly causing this fault I would guess.

 

[siteguru]

An early member who will remain nameless (who was banned) had similar issues which were never resolved and rejected the car.

He who shall remain nameless .. his car's fault symptoms weren't quite like this though; I don't recall him ever reporting a Motor Fault.

 

[zaktaylor]

He who shall remain nameless .. his car's fault symptoms weren't quite like this though; I don't recall him ever reporting a Motor Fault.

To be fair it looks like a Motor Fault is a rare occurrence on the MG4 not many mentions of it online. I think its strange that the car wont store the fault as such. Strange that it flashes on and off almost like a glitch. leads me to think its a sensor misbehaving to be fair.

 

[Bam Bam]

To be fair it looks like a Motor Fault is a rare occurrence on the MG4 not many mentions of it online. I think its strange that the car wont store the fault as such. Strange that it flashes on and off almost like a glitch. leads me to think its a sensor misbehaving to be fair.

Hope it proves to be an easy fix.

The problem with all these sensors in cars these days is that when one goes the car doesn't work properly until it is replaced. Sensors gradually fail over time for one reason or another so there will be more and more of this kind of thing.

Not an EV-specific thing, or even that recent as we had a sensor fail in our old Seat Ibiza over 10 years ago and it threw up the "check engine" sign all the time.