HELP! Hybrid won't start after disconnecting 12v

[Tacomonkey]

I installed power running boards on my 24 hybrid and now the truck won't start. I'm panicking, checked the manual before and IDK what to do now, any advice? I get power to the cluster, but when I press the brake and try to start it keeps saying parking brake unavailable

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[Gear_yyc]

Did you check the voltage? If it's a bit low, it may have enough to power the cluster, but not the brake or starter.

 

[Tacomonkey]

You

Did you check the voltage? If it's a bit low, it may have enough to power the cluster, but not the brake or starter.

You think that could also cause warnings about the braking system power and the parking brake?

 

[Sagebrush]

You think that could also cause warnings about the braking system power and the parking brake?

Well, I sure don't know why the system would throw out that light, but modern trucks do odd things when something is amiss.

Did you run the steps several times before trying to start the truck? That could have run the voltage down. I'd test the 12-volt battery's voltage and top it off if it's below 12.6 volts.

My truck's the gas version, so I don't quite get the hybrid system. Does the 12-volt battery look to be of normal size? Maybe a Group 24 or so?

 

[rchrds]

You

You think that could also cause warnings about the braking system power and the parking brake?

There have been reports of a whole christmas tree of error lights when the 12V start battery goes low, so this is certainly not out of the realm of possibility.

 

[gpburdell]

Disconnecting the 12V battery typically shouldn't do anything, and is recommended whenever doing any electrical work, especially anything near any of the airbag components..

First - check the 12V battery voltage - if it's above 12.4V or so it's fine.

Next check fuse block - make sure you didn't inadvertently blow or dislocate one of them when tapping into power.

Lastly check all connectors anywhere near where you were working to see if you might've dislodged or disconnected one of them.

 

[trailhunger]

Probably a low battery. I had this happen when wiring accessories & running GFc lights for an extended period. Dash went full Xmas tree, battery was low / disconnected/ trickle charged overnight / errors slowly cleared throughout day after a few restarts & driving around town

 

[Tacomonkey]

There have been reports of a whole christmas tree of error lights when the 12V start battery goes low, so this is certainly not out of the realm of possibility.

Probably a low battery. I had this happen when wiring accessories & running GFc lights for an extended period. Dash went full Xmas tree, battery was low / disconnected/ trickle charged overnight / errors slowly cleared throughout day after a few restarts & driving around town

These posts give me hope, it does seem to die completely after the initial round of lights and they say the hybrid batteries are nominally low anyway, around 12.2. I can't find my meter so I put it on a trickle charger and crossing my fingers it's just low. Thanks everyone, wish me luck

 

[TacoFreak]

Yeah, my 12 volt is almost always around 12.2 volts. Hybrids don't usually start from the 12 volt but from the hybrid battery, so it seems like your 12 volt is maybe too low to operate the electronics. Hopefully your trickle charger will provide enough charge to get the system running again.

 

[gasgasman]

Turn the ignition on and cycle the parking brake.

 

[Kubiedo]

Did you directly connect to the battery under the seat?

You can test if you're getting power to the fuse/relay box on the passenger side of the engine bay (right in front of the hybrid system). If you lift the cover of the box, you will see a lone screw at the top (closest to the fender), which is powered. With a multimeter, touch the screw (with positive) and touch the grounding screw that's against the fender panel to check the voltage.

This will tell if you have a break in power between the battery and the rest of the car.

 

[Tacomonkey]

Got it started, definitely low 12v battery. Trickle charged overnight and it fired right up this morning, no codes, so relieved! Thank you all for the replies! This may put me off doing any electrical upgrades in the future lol. Thought I bricked my baby!

 

[mikeymtbs]

Glad to hear. Now, tell us which power running boards did you install?

 

[Tacomonkey]

Glad to hear. Now, tell us which power running boards did you install?

Lol they're the Go Rhino/real truck boards, I may take some pics and post a thread to help others that may want to do it, the install directions were not ideal as they all picture 3rd gen Tacomas. From what I can tell, they are exactly the same as the Ionic and Westin boards, just at different prices and with different warranties. All the install directions, parts lists, etc are basically identical. They look pretty good, I wish they tucked up a bit closer like the OEM rock guards, but I may be able to adjust that, I have to take a look later. TBH I didn't want any steps, it's a compromise for the family members I need to occasionally drive. Though the truck does sit surprisingly high, I'm sure there's days I'll be very glad I don't need to literally hop into it

 

[larkhen]

Lol they're the Go Rhino/real truck boards, I may take some pics and post a thread to help others that may want to do it, the install directions were not ideal as they all picture 3rd gen Tacomas. From what I can tell, they are exactly the same as the Ionic and Westin boards, just at different prices and with different warranties. All the install directions, parts lists, etc are basically identical. They look pretty good, I wish they tucked up a bit closer like the OEM rock guards, but I may be able to adjust that, I have to take a look later. TBH I didn't want any steps, it's a compromise for the family members I need to occasionally drive. Though the truck does sit surprisingly high, I'm sure there's days I'll be very glad I don't need to literally hop into it

quick question to you, how did you disconnect the battery? I'm trying to do a switch panel install. Did you take off the whole thing from the negative terminal or just the wire that's attaching to the chassis? (I’ve attached a photo with red being the whole thing and green of just the wire to chassis) Did you also take off the positive terminal?

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