CEL code P13D7 and P13D9

According to the dealer here I need a new Harness, his words exactly

"Found Fault codes for cyl 4 internal pressure sensor electrical faults. Wiggle test glow plug harness and confirmed terminals in glow plug harness are losse causing interuption of cyl 4 pressure sensor readings. Must replace engine harness."

Service rep quoted me a shade above $1400 for the repair. I declined.

Car: 2010 Jetta TDI, 93K all regular service perfomed, no prior issues. seems to be running fine.

Should I replace the harness, get a second diagnosis, or drive it anyway and wait to get stranded one day and finally use that roadside assistance I pay for month after month?

terminals can be loose in connector as long as they have good contact plugged onto the glowplug pins. I would disconnect the #4 glowplug and look to see what the terminals in the harness look like (burn-arcing marks or corroded). remove #1 and compare. many have had glowplugs (pressure sensors) fail. seems common, myself included. if anything try a glowplug, At $100 seems like it would be an easy try before spending $1400.

wiggle the harness yourself.....does it feel any different than the other 3 ?? But there have been a few harness failures on the 09-10 cars so they could be right. He is standing there touching the car.....I am across the country looking at a crystal ball.

I have looked around and seen a lot of folks that had this problem replaced the #4 glow plug and solved the problem. Is there any way to troubleshoot this to see if it is the harness vs. the glow plug? My harness looks great, no signs of mice of heat wear.

swap #4 and #1 glowplugs and see if the problem codes change to #1. they are very simple to remove and install. the connector and a deep socket, less than 5 minutes. it would be normal to swap the plugs and all problems go away for a while. when the pressure sensors go out they seem to come and go for a while before total failure,

If you don't have something to erase the current faults and turn the check eng light off your new faults will probably say #1 and #4 because of the old faults stored for #4 and the new faults for the swapped plug in #1.

if after swapping the glow plugs the fault still stays on #4 then the problem is in the wiring.

the reason I suggest 1 and 4 is because there would be no chance of getting wires connected back up wrong or accidently mixing up swapping #1 and #2 instead of #3 and #4 which would throw your troubleshooting all off.

Good suggestions. ill report back.

update: I took the car to an independent shop (Charleston Wagen worx) and they seemed to think it was just the glow plug, also had them do the tmiimbng belt and oil change while they had it because I am at 100K and why not. Out the door it was $1,300 which I was pretty happy about, cheaper than the dealer would have charged just to fix the CEL. Car is great now, drives better and I ahve my piece of mind