Click pics if needed to enlarge.
1: If it starts but won’t charge: (if it won't even start, skip to #2 below)
*
![Bumper Automotive exterior Font Rectangle Gas]()
2: If you hear a little "clunk" or "da-dunk" when you open the left door skip to #3 (otherwise, do NOT skip this step!)
If not, continue here: No clunk means the 12V starter battery isn’t connecting the High Voltage battery contactors, as needed to charge or start the car. IF you wait several seconds after opening the door, to hear the disconnect clunk, THEN there should also be a clunk:
If not, continue here: Just like any gas car, a low 12V starter battery is the most common cause of failure, including inactive contactors. Even when it's technically "dead" by gas car standards, a 500e will often start but sometimes with errors, & the 12V can fully die without warning after normal use for only 2 years, so after that it’s good to have a little $50 portable jumpstarter:
![Font Auto part Rectangle Fashion accessory Event]()
Even after a parts store does a load test with good results, the voltage can still be too low, so you have to check it. Grab each end of the black plastic motor cover & yank it straight up like you’re lifting a laundry basket full of wet clothes. It’s almost unbreakable, but completely useless, so I leave mine in my garage closet. After the 12V is 2 years old, check it periodically, to avoid failure. If you’re stranded, it sometimes works if you leave the door latched only 1 click (to avoid “wake-up” signal), turn off the headlights, wipers, & dome lights, wait about 15 minutes & try again.
![Watch Light Vehicle Hood Automotive tire]()
Left, Amazon "multitester", starting at $10.
Right, $22 BatteryTender.com gauge.
B) Enable the contactors with the $50* AlfaOBD app from Google Play Store. The contactor disable glitch seems like it could be from aftermarket EVSEs** or a low 12V, & is VERY rare compared to “A” above.
If you only have an iPhone/iPad, try a laptop/tablet, or ask your friends if they have an old Android, or get one for $15 on Amazon. No service needed, just download the app on WiFi. A $17 eBay ELM327 KONNWEI KW902 will connect it to the car:
![Product Rectangle Font Screenshot Line]()
![Rectangle Slope Font Line Water]()
*1 user reported the free "demo" app worked, but then 2 others reported it didn't.
**Avoidable by using the OEM EVSE, which fully recharges overnight from ZERO%, with an easy-DIY $13 adapter in a 240V outlet like an aftermarket L2 uses.
3: If the humidity sensor is left unplugged, skip to #4 (otherwise do NOT skip this step!)
If not, continue here: It’s just at the right of the rearview mirror & causes many false alarms, including ABS, RBS, ESC, HSA, PRND, SRS (airbag) etc. Put your middle fingers in each opening near the top & pull perpendicular from the glass:
![Circuit component Electronic engineering Machine Hardware programmer Computer hardware]()
With a tiny screwdriver or round toothpick parallel to the glass, stick it straight into the black socket to wedge it open & remove the purple plug.
Even though you LEAVE it unplugged, the cover fits, with its left side hooked on & then the right side snapped upward perpendicular to the glass. Hook/snap points circled in pic.
4: "Clear Faults" AFTER steps 2 & 3 above, with OBD or multiple key cycles. With OBD it sometimes requires clearing 2 or more separate control units, 2 or more times each, before it stays clear:
![Product Font Line Rectangle Screenshot]()
If you don't have OBD, codes will often clear with the key off for 3 minutes. Repeat if needed, up to 10 times, but usually ONCE works for me, & the most I've ever needed is 3 times, off for just 1.5min for the screen to go fully black (not just really dark grey), but other users report needing 3 min, 5-10 times.
5: Reboot via 12V disconnect AFTER steps 2 & 3 above, & after the key is off for 3-min. Disconnecting it for 30 seconds worked for me, but when that failed for someone else, & so did 30 minutes, 30 hours worked. Ideally, disconnect the NEGATIVE, since it’s more robust, & it won’t short out the 10mm wrench (or even pliers, in a pinch) on any surrounding metal. Retighten it until you can’t twist it off of the post by hand.
6: Reboot via HV disconnect AFTER steps 2 & 3 above: (orange plug under rear seat bottom)
![Automotive tire Light Bumper Automotive exterior Rim]()
a) With the car in "ready" mode if possible, open the hood & left door & don't open or close anything else* for the entire process, to avoid "wake up" signal.
b) Remove the key, wait 3+ minutes for "sleep" mode.
c) Disconnect HV, disconnect 12V 30+ seconds, connect HV, connect 12V.
IF that doesn't work, there are at least 3 other sequences to try, but for ANY of them make SURE to first ALWAYS do steps A & B above, & check car function after each one before you continue:
c2) Disconnect HV 30+ seconds & reconnect. Disconnect 12V 30+ seconds & reconnect.
c3) Disconnect 12V, disconnect HV 30+ seconds & reconnect, connect 12V.
c4) Disconnect HV, disconnect 12V 30+ seconds & reconnect, reconnect HV.
* I thought that only the left door woke it up, since it's the only one that awakens the HV systems (contactor clunk), HOWEVER the other door and even the hatch can awaken the 12V systems (instrument screen lights up).
I posted this when a fellow user's "dead" car was at a DEALERSHIP for a MONTH, he informed them about one of these procedures that requires a few taps on a free phone app connected to a $17 dongle, & THAT is what got the car running
.
CONTENTS:
1. Charge Failure ONLY
2. Contactor “Clunk” A) 12V Starter Battery B) Disable Glitch
3. Humidity Sensor
4. Fault Clear
5. 12V Reboot
6. Main Battery Reboot
1. Charge Failure ONLY
2. Contactor “Clunk” A) 12V Starter Battery B) Disable Glitch
3. Humidity Sensor
4. Fault Clear
5. 12V Reboot
6. Main Battery Reboot
1: If it starts but won’t charge: (if it won't even start, skip to #2 below)
- Check the J1772 socket AND plug for damage & bent or corroded connectors.
- Deactivate the charge timer in the car’s menu. It can default itself to “active”.
- Plug into the OEM unit*. It can reset some charge errors.
- Reboot the charger via reset button, unplug/replug, or circuit-breaker off/on.
- Try a different charger.
- Turn the car on before plugging in (necessary if the battery pack is below -14F)
- Turn the car off for 3 minutes & back on.
*
2: If you hear a little "clunk" or "da-dunk" when you open the left door skip to #3 (otherwise, do NOT skip this step!)
- When you turn the key on, & another clunk several seconds after you turn it off.
- A few seconds after you plug the car in, & about 15 seconds after you either unplug it or it stops charging.
If not, continue here: Just like any gas car, a low 12V starter battery is the most common cause of failure, including inactive contactors. Even when it's technically "dead" by gas car standards, a 500e will often start but sometimes with errors, & the 12V can fully die without warning after normal use for only 2 years, so after that it’s good to have a little $50 portable jumpstarter:
Even after a parts store does a load test with good results, the voltage can still be too low, so you have to check it. Grab each end of the black plastic motor cover & yank it straight up like you’re lifting a laundry basket full of wet clothes. It’s almost unbreakable, but completely useless, so I leave mine in my garage closet. After the 12V is 2 years old, check it periodically, to avoid failure. If you’re stranded, it sometimes works if you leave the door latched only 1 click (to avoid “wake-up” signal), turn off the headlights, wipers, & dome lights, wait about 15 minutes & try again.
Left, Amazon "multitester", starting at $10.
Right, $22 BatteryTender.com gauge.
B) Enable the contactors with the $50* AlfaOBD app from Google Play Store. The contactor disable glitch seems like it could be from aftermarket EVSEs** or a low 12V, & is VERY rare compared to “A” above.
If you only have an iPhone/iPad, try a laptop/tablet, or ask your friends if they have an old Android, or get one for $15 on Amazon. No service needed, just download the app on WiFi. A $17 eBay ELM327 KONNWEI KW902 will connect it to the car:
*1 user reported the free "demo" app worked, but then 2 others reported it didn't.
**Avoidable by using the OEM EVSE, which fully recharges overnight from ZERO%, with an easy-DIY $13 adapter in a 240V outlet like an aftermarket L2 uses.
3: If the humidity sensor is left unplugged, skip to #4 (otherwise do NOT skip this step!)
If not, continue here: It’s just at the right of the rearview mirror & causes many false alarms, including ABS, RBS, ESC, HSA, PRND, SRS (airbag) etc. Put your middle fingers in each opening near the top & pull perpendicular from the glass:
With a tiny screwdriver or round toothpick parallel to the glass, stick it straight into the black socket to wedge it open & remove the purple plug.
Even though you LEAVE it unplugged, the cover fits, with its left side hooked on & then the right side snapped upward perpendicular to the glass. Hook/snap points circled in pic.
4: "Clear Faults" AFTER steps 2 & 3 above, with OBD or multiple key cycles. With OBD it sometimes requires clearing 2 or more separate control units, 2 or more times each, before it stays clear:
If you don't have OBD, codes will often clear with the key off for 3 minutes. Repeat if needed, up to 10 times, but usually ONCE works for me, & the most I've ever needed is 3 times, off for just 1.5min for the screen to go fully black (not just really dark grey), but other users report needing 3 min, 5-10 times.
5: Reboot via 12V disconnect AFTER steps 2 & 3 above, & after the key is off for 3-min. Disconnecting it for 30 seconds worked for me, but when that failed for someone else, & so did 30 minutes, 30 hours worked. Ideally, disconnect the NEGATIVE, since it’s more robust, & it won’t short out the 10mm wrench (or even pliers, in a pinch) on any surrounding metal. Retighten it until you can’t twist it off of the post by hand.
6: Reboot via HV disconnect AFTER steps 2 & 3 above: (orange plug under rear seat bottom)
a) With the car in "ready" mode if possible, open the hood & left door & don't open or close anything else* for the entire process, to avoid "wake up" signal.
b) Remove the key, wait 3+ minutes for "sleep" mode.
c) Disconnect HV, disconnect 12V 30+ seconds, connect HV, connect 12V.
IF that doesn't work, there are at least 3 other sequences to try, but for ANY of them make SURE to first ALWAYS do steps A & B above, & check car function after each one before you continue:
c2) Disconnect HV 30+ seconds & reconnect. Disconnect 12V 30+ seconds & reconnect.
c3) Disconnect 12V, disconnect HV 30+ seconds & reconnect, connect 12V.
c4) Disconnect HV, disconnect 12V 30+ seconds & reconnect, reconnect HV.
* I thought that only the left door woke it up, since it's the only one that awakens the HV systems (contactor clunk), HOWEVER the other door and even the hatch can awaken the 12V systems (instrument screen lights up).
I posted this when a fellow user's "dead" car was at a DEALERSHIP for a MONTH, he informed them about one of these procedures that requires a few taps on a free phone app connected to a $17 dongle, & THAT is what got the car running
.
