P1345 code and trans issues

[sarge77]

Hi everyone 99 yukon 4wd with two issues. I have the dreaded p1345 code and truck sounds like it's missing at all rpm. Where should I start with this code? And the hard one... While driving the truck makes a jerk randomly while driving between 45 and 75. Almost feels like it's trying to engage 4wd. The 2hi light never changes. It has the auto 4wd also. While driving I can hear the relay in the power junction box by the brake pedal clicking while the trans shifts...is this normal?

 

[SunlitComet]

you are misfiring over a misaligned dizzy. use the attached form to find and correct the issue.

 

[sarge77]

Thanks sunlit...any idea on the clicking selinoid?

 

[SunlitComet]

the clicking sound may be the brake/motor relays in the tccm but first can you describe this power box you mention?

 

[sarge77]

It's the power junction box down by your left foot on the firewall next to the brake pedal. It has one big relay and that is the one clicking every time the trans shifts. I have a bad feeling that the 4wd is either engaged or is trying to engage while I'm driving.

 

[SunlitComet]

that is the convenience center and that big relay is likely the flasher relay and should not be clicking at all unless signals are on. please post a pic or two with more detail to confirm and will go from there. other relays that might be there are drl lighting and fog lights relay if optioned.

 

[sarge77]

 

[SunlitComet]

that black box is the turn signal flasher.

 

[SunlitComet]

you are saying that is clicking when shifting gears?

 

[sarge77]

Is there anything else in that general area or under the dash that would click? You can clearly hear it..even the passenger can hear it.