2007-2011 Polaris IQ Snowmobiles Service Manual, Page 477Get this manual
Battery and Electrical Systems Over-VoltageVoltage Spike Test
The diode check test cannot be used to determine if the regulatorrectifier has supplied the ECU with voltage spikesTo determine if the regulatorrectifier has damaged the ECU with voltage spikes, the potting material on the backside of the ECU must be inspectedIf the ECU has been damaged by over-voltage, the potting material in the shaded region will be melted, discolored, or bubbledIf potting material is damaged in the shaded region, replace the ECU and voltage regulatorrectifier