V1 Intermittent No Power/Start

[Joebob]

I had many of the same codes when I went into limp mode while on a drive. Such things as Transmission faults, cruise control errors, and 3rd brake light. In the end it was the CANBUS in the lower pug of the BCM. It somehow got unseated on a harsh road dip.

See if this helps sort out the communication issue:

No Start Issue - B+ Terminal/Fuse Box

I don’t know. Nothing gets powered because it’s all shut down when doing the no start. I could clear them while it’s reset though I don’t think the codes are causing the no crank then. Check and see if you are getting power supply to the obd2. If nothing is powered up you have a wiring problem...

dfkitcar.com

Joe

 

[Gtstorey]

Most of the intermittent problems are caused by loose connections.

 

[jirwin]

Was reading here: http://dfkitcar.com/forum/index.php?threads/no-start-issue-b-terminal-fuse-box.3845/post-77048

It will "fix" itself if I turn the lights off auto. If the key is on before hand, the fuel pump will suddenly prime, relays click, and lights come on like normal

 

[jirwin]

Codes since clearing yesterday. Hasn't been driven. All I did was turn the lights on, didn't remove negative terminal like I have been.

0x544: B1380 (Current, History)
0x544: B2645 - Ambient Light Sensor Circuit (Current, Old, History)
0x544: U2113 (Current, History)
0x544: U2116 (Current, History)
0x544: U2125 (History)
0x544: U2172 (Current, History)
0x7E8: P0036 - HO2S Heater Control Circuit (Bank 1, Sensor 2) (Permanent)
0x7E8: P0443 - Evaporative Emission System Purge Control Valve Circuit (SES, Pending, Current, Old, Permanent, History)
0x7E8: P0449 - Evaporative Emission System Vent Control Circuit Intermittent (SES, Pending, Current, Old, Permanent, History)
0x7E8: P0452 - Evaporative Emission System Pressure Sensor/Switch Low  (SES, Pending, Current, Old, Permanent, History)
0x7E8: P0532 - A/C Refrigerant Pressure Sensor A Circuit Low (Pending, Current, History)

The only somewhat relevant ones seem to be `B2645` and `B1380`. I forget, do we retain the ambient light sensor? I feel like we do somewhere.

`B1380` shows this:

Might be that I shorted something in the ignition harness? I didn't have running light when I finished the car. I messed something up along the way. So I ran a new wire from one of the key on 12v sources to power the tail lights. This started happening after I left the key in all night, and I think I had my new DIY tail light prototypes on. Its possible that they pulled more current than intended and burnt up and shorted. Unlikely, but I suppose its possible. I'm going to snip that wire at the BCM and see if it stops.

 

[Gtstorey]

Ambient light sensor shouldn’t matter.
It looks like the B1380 code might be a problem. The best I can tell that is a problem with the accessories circuit off the ignition switch to the bcm. And also feeds the power to the theft deterrent module.

Check the 40a bcm2 fuse in the rear fuse box, check the 2amp fuse 8 of the bcm. If that is good, check for power at pin 4 with the switch in accessory, and then check it x4, c8 of bcm and pin 2 of the TDM. It would be better to check these with a test light than multimeter.
If you tied in your tail lights on a relay control Controlled circuit it should be ok. If it is on the control side of the relay you could have burnt something up, although more likely shot a fuse.

 

[jirwin]

Had a few minutes tonight to dig into some stuff. I check continuity all the way from the taillight to the accessory pin at the BCM. Confirmed continuity. Checked to see if the pin got power, and it didn't. Checked all BCM fuses and found a small 2A one popped. Don't have small fuses on hand, so replacing that will have to wait until tomorrow.

 

[Gtstorey]

What pin did you have the lights attached to?

 

[jirwin]

What pin did you have the lights attached to?

I believe B5 (Brown)

 

[Gtstorey]

BCM X3 B5 runs to the Trans Control Module and the ECM and not designed to carry a load. I don’t think anything on the BCM is appropriate to carry a load directly. I’m not sure if you spliced in or if you have a manual so had a spare wire.

 

[jirwin]

Spliced it in. I'll probably switch it over to my auxiliary fuse box I added for the heat exchanger, radio, wideband, and USB charger.

BTW looked up the 2A fuse and its "IGN SW/PK3+ Fuse 2A Ignition Switch". Probably my code.

 

[Gtstorey]

That is the fuse that I referenced so likely the the cause of your code. Don’t know if it will solve your bigger problem. But turning your lights on may back feed power to that circuit and make it work. Basically it’s hot wiring the the car.

 

[jirwin]

Replacing the fused fixed my taillights as expected. I still will be putting it on a proper key-on fused power source since its not much work. We will see if it fixes the starting issue too

 

[Gtstorey]

I would not run it all with the tail lights tied in as you have them.
Any reason you can’t tie them to fuse box X5 D1 or X3 C1?

 

[jirwin]

Nope no reason, just did it wrong the first time. Overzealous guy with his fancy new multimeter saw 12V key on and said "Yep!"

 

[Gtstorey]

The pins I mentioned before is where the parking lights originated on oem.

 

[jirwin]

OK... After going thru it I remember why I did what I did. I did just see 12V key on and call it good, but because the park lamp wire had no power. I wired something wrong along the way and it wasnt receiving any power. So, I tapped into what i thought was the next best thing - wrong.

On the plus side, the car isn't doing the intermittent start thing anymore. Leaving it the bad way I had it, and letting it sit for a few hours, it powered right back on with the turn of the key as expected. I'm still not sure why this was causing the whole thing to shutdown, unless it was going into some sort of protect mode. Regardless, glad to have the issue solved.

 

[Gtstorey]

I don’t see anything in wiring diagram to indicate what the back feed might be doing that would cause intermittent problems but maybe something in the bcm is getting warmer than expected.