I-Miev 2011 Jerks after OBC repair

[xbeetlejuiice]

Hello!

My friend has a problem with his I-Miev. A few days ago, the car shut off while driving. The 12V was depleted due to DCDC and OBC malfunction. We replaced the OBC with a model manufactured in 2018, so that one should be fine for a long while HV fuse also had to be replaced, no big deal since we could quickly get our hands on one.

Now, the car generally drives. No error codes. Charges fine.

The only weird thing we noticed is that the car jerks while driving. Anyone know what that could be? Never noticed that before.

 

[kiev]

That is a new one for me, never heard of that before. If no DTC code is being thrown then i would suspect a loose wire or contact in a connector, rodent damage or cut in a wire, etc.
Did yall replace the 12V or still trying to use the old one?

 

[jray3]

The only drivetrain jerks I've experienced after two OBC replacements are when one shifts from Reverse to Drive while the car is still in motion, which caused the motor to lash back and forth, gradually petering out. nEVer anything but smoothness during acceleration beyond that false start caused by eager shifting.... That's 'normal' for our cars.

But it sounds like your jerk rears up during constant forward motion?

 

[xbeetlejuiice]

Thank you both! I at first also thought it was the 12V, we exchanged that with a known good one. The car has not been driven in the mean time. Now, it is completely bricked and doest even "Start", the only thing it still does is charge with AC. A ton of fault codes:
U111B, P1AC5, U1113, U1080, U1160, P1B09, P1B32.

All related to some type of CAN time-out. Any tips? I don't think its related to the obc anymore.

Thanks!

 

[kiev]

Has anyone removed the rear seat and been messing around with the connectors and wiring. There does appear to be CAN Buss issues; use a DVM to measure the voltage directly at the 12V battery terminals when you turn the key to ACC, ON, and START to see if it is being pulled down by something. De-mate and mate all the connectors in the engine bay and under the rear seat [with the key OFF and the 12V battery disconnected first]. Inspect for corrosion and clean contacts, check wires for breaks and cuts, etc.

Some DTC notes from the FSM:
When the diagnosis code No. U111B is set to the BMU, the diagnosis code No. P1AC5 will be set.

Also,
If the smooth condenser voltage (the big black capacitor in the MCU) of 380 V or more continues, the diagnosis code No. P1B08 will be set.

And,
DIAGNOSIS CODE SET CONDITIONS
If (the EV-ECU) cannot receive from (the MCU) the chassis number registered in the EMCU, the EV-ECU sets diagnosis code No. P1B32.
PROBABLE CAUSES
EMCU malfunction
EV-ECU malfunction
Wiring harness or connector failure of CAN bus line

 

[xbeetlejuiice]

Thanks for the tips! We were able to find the connector causing the issue, the car (unfortunately) had some damage in the past, and the guy repairing it couldn't have been an expert. We were able to locate the issue at the connector to the DC-DC. Ill try to attach a picture. He destroyed the connector and (presumably) put in other pins since they were loose.

 

[xbeetlejuiice]

Thanks for the tips! We were able to find the connector causing the issue, the car (unfortunately) had some damage in the past, and the guy repairing it couldn't have been an expert. We were able to locate the issue at the connector to the DC-DC. Ill try to attach a picture. He destroyed the connector and (presumably) put in other pins since they were loose. https://imgur.com/a/r69dbCz