Tesla Roadster PEM Upgrade and Aging Issues

June 23, 2019

As first generation Roadsters continue to age, some of the Power Electronics Modules (PEM) are reaching 11 years of age. There are components in this large electronics module that have deteriorated and are end of life, and overdue engineering change orders that if left unresolved, can cause failure or damage to a major sub-assembly no longer in production.

Deteriorating and crumbling transistor insulating material is the most compelling reason to get a PEM upgrade. As the barrier deteriorates, the power transistors eventually short to ground, disabling the car.

Electrolytic Capacitors are the next in line. These components have a 7-8 year shelf life, and an even shorter service life when subjected to a harsh uncontrolled environment in a car.

PEM upgrade items:

Newly discovered PEM issues including Firmware upgrade:

As Tesla Roadster PEMs age, new issues are surfacing which were not yet revealing themselves at the time of this newsletter publication.  Included are the new PEM upgrade items listed below, and DC input and drive motor output block deterioration which we will cover in an upcoming newsletter.

ESS Battery Pack Coolant Tip

We have had two Roadsters where coolant reservoirs were nearly empty. Both were exhibiting noisy pumps. In one case, the low coolant level, and subsequent ESS pack overheating, caused an APS (DC-DC Converter inside the ESS pack) to fail.

The solution from Tesla was a $30K ESS pack replacement. We pulled the battery pack and repaired the APS to component level. Pay attention to your coolant levels.