Motor Fault Consult Handbook P1B65 DTC code

[Eddy P]

I'm the owner of a MG ZS EV 2020 model and since yesterday received a RED warning message on the display. "Motor Fault Consult Handbook". The Handbook tels me to contact an MG Dealer. Calling the MG Dealer they tell me that they have time to look at this in 5 weeks from now.
With my ODB-II reader I found error code P1B65. On Youtube there is one post that explains the code in general "Battery Circuit High Voltage". Not Specific to a MG ZS EV. Can someone tell me what this Code means for an MG ZS EV in detail please?

 

[Eddy P]

UPDATE: ODB-II reader tells me the DC battery voltage is 442 volts. Not sure if this is within the treshholds. SoH for the Battery is 88%

 

[Coulomb]

ODB-II reader tells me the DC battery voltage is 442 volts. Not sure if this is within the treshholds.

Assuming that yours is pre facelift, the max voltage should be around 449V, though mine goes to 451V after a software update. Pre that update, the limit was 455V. So it doesn't seem that your problem is the total battery voltage.

My guess us that one or more of your cells is going over the cell voltage limit, which is likely around 4.21V or so. Has your battery been balanced lately?

Edit: But battery voltage doesn't seem to be related to a motor problem. So my next guess is that P1B65 isn't what that video says it is. All that is standardised about these sorts of trouble codes is that P stands for Powertrain. Each manufacturer seems to be free to define each code how they please. You may have to gain access to a service manual to find out what the trouble code actually means.

Member siteguru has kindly made available several MG4 manuals; it's likely but not guaranteed that the codes mean the same across several MG EV models.

 

[Eddy P]

Assuming that yours is pre facelift, the max voltage should be around 449V, though mine goes to 451V after a software update. Pre that update, the limit was 455V. So it doesn't seem that your problem is the total battery voltage.

My guess us that one or more of your cells is going over the cell voltage limit, which is likely around 4.21V or so. Has your battery been balanced lately?

Thank you for your swift response. I'm gonna check cell voltage now to check mine. The battery balancing: the only way I know how to balance it is to provide a full charge to the car and the balancing will happen automaticaly. Is there another way to balance the battery?

 

[Coulomb]

Is there another way to balance the battery?

I'm not aware of any. As long as you were charging to100% every month or two and leaving the power on, the cells should be adequately balanced.

As i said later in my post, I think that the best strategy is to chase down what the P1B65 trouble code actually means.

 

[hmadsen]

If you have a suitable dongle and the eZS program you should be able to see what the imbalance of the cells are.

Last time i checked the difference between the one with the highest voltage and the one with the lowest, was 0,07 volts for example.

 

[fred12345]

I'm the owner of a MG ZS EV 2020 model and since yesterday received a RED warning message on the display. "Motor Fault Consult Handbook".

This happened when you started the car or whilst driving?

How many times you got this? Happens every time you start the car?

 

[Coulomb]

I had a quick look for P1B65 in the only MG4 manual that mentions Diagnostic Trouble Codes, and it did not include P1B65.

The closest was P1B69, "ESS Cooling Pump not Lifebeat", which I presumes means that the HV battery (Electric Storage System, ESS) has a pump that it supposed to send a CAN bus message that "all is well" (typically called a heartbeat message), but that message was not received.

All we can gather from this is that P1B65 may be something associated with the HV battery, and possibly the cooling system for that battery. I suppose you could check the level of the coolant reservoirs. There are about 3 of these, one will probably be exclusive to the HV battery. If one is low, that might indicate that the problem isn't urgent in winter, although the battery heating might be affected.

 

[Eddy P]

FINAL UPDATE: Thank you all for your reply and sugestions, love the Forums. I took the Car to a MG Service center in Waalwijk in The Netherlands. Excellent support. They made time in their busy schedule to find the root cause. A defective cooling pump. Pump replaced in 1 week and part of the 7 years MG warranty. No cost. Excellent support !

 

[Coulomb]

A defective cooling pump.

And presumably related to the motor and/or its electronic controller, given the motor fault warning. Indicating that trouble codes may not be common across MG models.

Great to hear that you're back on the road, and thanks for the update.