Sorry I should have clarified. That is from b- to p13
Technically 1.3 volts should be enough drop to clear the code, however, there is no reason it should not be zero. The switch connects B- and p13.
Make a solid connection right at controller for a test. If it clears code find where the poor connection is between B-, switch, and P13.
If bringing P13 to zero volts does not clear code, it is a problem in controller. IMO very unlikely.
I have a T1 here to do a test, but is too time consuming for forum help. 
ps.
I donât know where the switch gets itâs B- wire. Green. You might try replacing green with another wire right from battery negative B-.
To me it looks like B- goes from switch to controller as well as spliced from controller to battery charger. Is there a way to disconnect the green and white wire from the 23 pin plug maybe I just need to replace both wires with new wire and maybe a direct connection to a battery negative.
Make sure it works first by connecting P13 to B-. If that doesnât fix it, it wonât help to rewire.
The only wire needed at controller for -04 function is P13. The B- can come from anywhere. The controller is connected to B- with big battery cable.
A direct connection from battery, replacing the green on the switch is an option.
Ok I tested the p13 and my numbers were different must have been doing it wrong p13 plus b- was 4.5 brake on 3.3 brake off.
Ok, thatâs the problem then.
Should go to zero (B-) when brake is off.
Try connecting WG wire directly to battery B- at switch. If that doesnât pull voltage at p13 to zero, wire has bad connection or has been stretched.
Now that you know the problem, you can look for code to clear rather than checking voltage.
Connected wg and b- at switch and still got -04 code at 3.7 volts
Thatâs because you still have the problem.
You must have zero volts to clear the error.
One of the wires has high resistance.
Check voltage at the switch with wg and b- connected.
If itâs 3.7v then b- wire is bad.
If itâs zero then wg is bad.
Iâll invite another opinion. I donât seem to be communicating well.
Nope your doing great! Iâm just making sure I donât do something wrong and damage the car so Iâm just giving as much info as I can at every step.
Ok, thanks.
The main thing is to pull P13 down to zero volts. It is held high by controller. Controller knows the brake is released when it sees a data low signal. That is done by âshortingâ pin 13 to battery negative B-.
The switch does this. However if there is not a good connection all the way thru the circuit. B- to switch. Thru switch. Back to controller. The âbrainâ doesnât know brake has been released.
There could be âbrainâ damage. We wonât know until you get p13 to zero.
Hey just wanted to say Inwo is tha man!!! Because of you and your skills my car is up and running! Your the best! Now I have to figure how to get the charger working if anyone knows zivian charger just beeps when plugged in
I have a 2007 gem e4 code 4 wont go off looked on controller and pin 13 has no wire going to it
T3 and up donât use p13.
Manual doesnât show -4 error code.
Are you sure of controller type? When did it quit?
Hi
if you get code 04 on a 2007 car,you have wrong software
and need a jumper
have a look here http://www.fsip.biz/IC3645SR7A353T4ForGEMCars_sm.html
I just bought a 2000 Gem 4 seater. It had a ride4fun motor that sparked when engaged. I bought a replacement motor. The same 7.5hp motor from ride4fun. I installed it and now I am having the -04 brake switch error. I checked alignment of the ebrake switch and wiring at switch. All seem good to go. Now I canât get it to clear the -04 code. Not sure why. It worked before when motor wanted to move but threw sparks. Would it be just a coincidence that the switch went bad? Iâm not sure. I hope itâs not the controller all a sudden.any ideas why this would happen after installing a new motor?
I wanted to dig deeper and try my hand at reading voltage on the wires with a multi meter. Was feeling cute and put the black probe in the green wire and then when I touched one of the other wires there was a spark and then I heard the CLUNK and now itâs working just fine! LOL. I seriously tried crossing the wires every which way and got nowhere. I just have a magic multimeter. I still havenât learned how to use it but that was amazing. Gotta have the right tools I guess. Put new batteries in last night and went for a cruise at 40mph at 3am through my neighborhood!!! Awesome!!!