Help!!! No crank or start

[hialeahzbg]

So I have a 2025 FL5 with FBO and flashpro. Yesterday I had my friend install a dw300 fuel pump and spark plugs but now the car won’t start or crank. I’m getting code U0100, all the fault lights are displayed on the dash and radio is asking me for a code(holding the power button down isn’t clearing the message)

what could it be.. it drove and started perfect prior to spark plug and dw300 fuel pump.

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[Superhatch]

" When a vehicle has U0100, most of the time, it won’t run or drive anywhere. The most common causes of U0100 are a bad PCM/ECM or TCM. It can be an exceptionally difficult code to diagnose. "

Did you disconnect ground from your battery while you did the fuel pump work? I would check grounds, check battery to ground, then check voltages and grounds at the fuel pump also. Hopefully just some bad wiring/connection, worst case scenario is you fried your ECU.

 

[Blindeye_03]

I would probably start by installing the old fuel pump and plugs...

 

[jtlctr]

Was there any wiring harness plugs disconnected in the engine bay? If so, make sure they’re reconnected and fully seated.

 

[ctechauto]

Was about to post exactly what @Superhatch posted.

Did you disconnect the battery prior to starting the work? Definitely could have shorted something out and hopefully you didnt fry the ECU if it did indeed short out

 

[hialeahzbg]

Everything looks good and still no ecm/pcm communication.. do ecu go bad so fast? Does a jailbreak go bad so fast? Anyone else have this issue?

 

[menikmati]

Everything looks good and still no ecm/pcm communication.. do ecu go bad so fast? Does a jailbreak go bad so fast? Anyone else have this issue?

Follow the suggestions that @Superhatch provided and check your fuses.

I'll be the third person to ask: Did you disconnect the battery prior to installation?

The ECU didn't "go bad" on its own and the jailbreak has nothing to do with it. Electrical gremlins are the worst to troubleshoot.

 

[PointByPatrol]

Have you checked the fuses? It's possible you popped a fuse when installing the parts. IIRC the vehicle will not crank when the fuel pump or injector fuse are removed. If it turns out to be a burned fuse, then replace the fuse and see if it pops again. If it pops again then I would suspect that you have a defective fuel pump.

 

[hialeahzbg]

Yes all fuses were checked and none popped

 

[PointByPatrol]

Yes all fuses were checked and none popped

Relays?

 

[jtlctr]

If you had reflashed the ECU previously with Hondata, it’s very possible that U0100 code was already there before your current issues, so I wouldn’t necessarily connect the code with your car not starting. I’ve reflashed my car numerous times and that code pops up after every reflash and doesn’t come back once cleared. I’ve read of other Type R owners noticing the same.

 

[hialeahzbg]

But I’ve been driving with the jailbreak and it’s been perfect.. this happened randomly

 

[TypeRD]

But I’ve been driving with the jailbreak and it’s been perfect.. this happened randomly

Sorry, but this is not a random occurrence, dude. There’s clearly a correlation between the work your friend did and the car not starting since then. Time to retrace steps. Put the old fuel pump back in. If that doesn’t work, put the old plugs back. If that doesn’t work…well…probably time to have someone who is good at diagnosing electrical issues take a look.

 

[hialeahzbg]

Yea battery was disconnected and he retraced steps as well…no issue

 

[PointByPatrol]

Yea battery was disconnected and he retraced steps as well…no issue

This is probably something you've already tested, but if all of the relays and fuses are good...have you tested the battery? Can communication errors can occur below 12v. And you need the proper amperage for the starter to spin. Have you tried jumping the car? Have you tried clearing the code to see if it returns?

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