RXV Locked Up Today

[Sigquick]

Hello, I have a 2016 RXV I need help with. It locked up today while driving. Flipped tow switch and put in neutral, still locked. Removed cover and unplugged the two connectors and reattached per instructions. That freed it up to roll and allowed braking while I towed it home. Batteries were at 63 percent so no a battery issue. Put wiring under cover back to original and toggle switch back to run. Fully charged batteries, still won’t run or roll. Checked plug under cup holder, it’s good, has continuity. I know it’s not batteries.

1. Since electric brakes worked towing home does that mean the brake is good?

2. How would I check the solenoid?

3. Anything else I should check?

[BobBoyce]

Originally Posted by Sigquick

Hello, I have a 2016 RXV I need help with. It locked up today while driving. Flipped tow switch and put in neutral, still locked. Removed cover and unplugged the two connectors and reattached per instructions. That freed it up to roll and allowed braking while I towed it home. Batteries were at 63 percent so no a battery issue. Put wiring under cover back to original and toggle switch back to run. Fully charged batteries, still won’t run or roll. Checked plug under cup holder, it’s good, has continuity. I know it’s not batteries.

1. Since electric brakes worked towing home does that mean the brake is good?

2. How would I check the solenoid?

3. Anything else I should check?

Just because the electric parking brake (Motor Brake) releases when bypassed, does not mean that it is good. The controller tests it every time you turn the key on, and if it does not pass the "twist test" at powerup, it will fail the test and prevent operation. Normal operation of the Motor Brake is at a lower voltage than the bypass operates it at. The bypass gives it full pack voltage, while normal operation is at a regulated percentage of that voltage. This is to prevent from overheating the Motor Brake during driving. It is an electrically activated "spring brake", very similar to the air brakes on a semi-truck/trailer setup. The brake is activated to unlock for driving, and deactivated for parking. Springs apply the brake when it is deactivated. Regular braking is from the AC electric motor while driving. The Motor Brake coil is nominally rated at 26.5 ohms, measureable with a digital multimeter. They can and do fail on a regular basis, as they are a maintenance item. Never replace an original (OEM) Motor Brake with an aftermarket or HD (Heavy Duty) version that is so common on eBay or from other sources, They are lower impedance and draw more current. Using one will typically fail the powerup "twist test", and it will eventually destroy your controllers Motor Brake output control FET. It is not repairable due to the hard epoxy used to seal the case on the newer controllers.

Bob