Damn it, another day, another issue, another code...P1296 and P0322, WTH?

[gt6974a]

2002 A4 1.8T 125K miles

Originally, temp gauge crapped out and CEL light came on, I had P1296 error and I first changed the 4 pin green coolant temperature sensor, no luck. Then noticed no heat so moved onto the Thermostat

I changed the Thermostat on Sunday, and bled the air out of the coolant multiple times/refilled....Temperature gauge is now working correctly and heat is coming into the cabin. Only issue I see is the fan comes on when I start and seems to run for about 5 minutes.

I had an emissions test last night and passed.

Today, go to an dentist apt., warms up fine on the way, come out after the apt., car won't turnover, takes about 3 times and then EPC and CEL come on. This also happened about a month ago before the thermostat went out but no CEL or EPC light came on, just took several times to crank. Thought my battery might be going bad. I actually remember unplugging phone/gps from power and then restarted (if that actually has anything to do with it)

I head to Advanced Auto Parts and the pop a P1296 - MCC and P0322.

Looks like the P0322 code is related to the Engine Speed Sensor

So, my questions are

1) Can the P1296 be related to the P0322?
2) Any ideas on why fan still runs on start up for a few minutes? Could it be b/c the lower coolant temp sensor?
3) I'm going to go by Audi and pick up the Engine Speed Sensor and replace tonight, anything else?
4) Do things tend to go out together on these cars? Should I anticipate changing anything else soon, or go ahead and replace something else now?

thx

[old guy]

The P1296 code indicates that the ECU isn't seeing what it expects to see based on input from the front and rear coolant temperature sensors. There is a discrepancy somewhere. For example, on start up the ECU measures the amount of air coming through the MAF and calculates the heat load that should be generated from the air volume. If after a given amount of time the temperature isn't where the ECU expects it to be you will get a P1296. Also, the temperature sensor in the lower radiator hose provides a signal to the fan control unit. Sounds to me like your 2-pin sensor is reading too high and causing the fans to run as well as the P1296.

I don't think the P0322 is related to the P1296. Two separate issues.

Good luck!

[gt6974a]

I just noticed in another thread on what to look for when buying a used A4, and someone said the following:

1. Broken dipstick funnell = oil mess under the intake manifold.
-These break and if they are not replaced in a timely manner you will more than likely destroy your Engine speed sensor(G28), knock sensor and/or tubing of your crankcase ventilation system.

I broke mine replacing the thermostat and replaced before putting everything back together. Some of the bottom of the old one got into the tube, couldn't get out, I wouldn't think this would cause much of an issue b/c of the oil filter, should I be concerned?

[Ethar]

changed the engine speed sensor.
I have had the same code p0322 , the car stalled on me few times the rpm was bouncing every now and then. changed the speed sensor and the problem weent away. got the speed sensor from the dealer for 87.00. if you have questions send me a page.