After a few weeks driving in rainy conditions the car didn’t start charging when pluged in. First it whould start charging after a few un-pulg and plug cylcles. But last week it wouldn’t charge at all.

Using the PEU Utility to read the error from the PEU.

PEU Stat shows IS2, IS2 Means that there is an isolation problem with the battery, e..g if the battery isn’t floating.

This can be tested with te following procedure

1. Connect 100 K-ohm resistor from battery (+) terminal to chassis
and measure voltage across resistor. Caution: resistor may get hot.

2. Reconnect 100 K-ohm resistor from battery (-) terminal to chassis and measure voltage across resistor. Caution: resistor may get hot.

If the propulsion battery is truly floating with respect to chassis, the voltage across the resistor should be near zero in each of the two above tests.

The first test was good but the second failed, there was a negative voltage of 94 Volt between the Minus Terminal of the battery and the chassis.

I disconnected all battery packs and measured them one by one. On the last one, the one with the negitave terminal connected to the PEU, I measured again 94 Volt.

It turned out to be corrosion in the main connector of the PEU.