2011 Audi A4 Quattro 2.0 T Code P2181

P2181 indicates that your Audi A4 has an observed cooling system temperature that is too high or too depression. It will come upwards in the browse tool as "Cooling System Functioning".

The trouble with P2181 is that past itself, it'southward not narrowing much down.  There could exist a problem with your A4's cooling system, temperature sensor, or even the ECU.

Audi A4:  P2181 Symptoms

• Engine overheating
• Engine too common cold
• No/low heat
• Stalling, crude idle

If the engine is stalling and running rough after getting this code, it is probable that the head gasket could be blown if information technology got hot.  If the engine is running cold it could run rough considering it's too rich.

P2181 Causes:  Audi A4

When left by itself (with no other trouble codes), there are many different issues that can cause P2181 in your Audi A4.  How you become about looking for them going to depend on if the temp guess is showing besides hot or too cold.  We'll go into that in depth in the diagnosis best practices section directly below.

Bad Temperature Sensor

Since the temperature is "out of range" it is very often the temperature sending unit itself that is causing P2181.  If your A4 is clearly overheating, the approximate should exist working fine, and you'll need to focus on why your vehicle is overheating.

E'er trust the gauge until you can verify that it is actually incorrect.  Never go out your A4 running while the approximate is showing that it is overheating.

Cooling Organization Issues

• Bad Thermostat–  The thermostat controls the amount of coolant that enters your A4'south engine.  If it stays open, the engine may never warm up all the style.  If it won't open at all, the engine will overheat FAST, unremarkably within a few minutes of the engine starting.
• Water Pump– If the water pump isn't working properly, coolant will non be able to motion through the engine and remove the rut, which can cause information technology to overheat.
• Bad Radiator– A clogged radiator will slow the flow of coolant and cause overheating.
• Low Coolant– If the coolant level is depression, there won't be enough to cool the vehicle.  Filling it dorsum upward volition temporarily solve the problem if the leak is small, and won't do anything if the leak is big.

Bad ECM/PCM/ECU

An engine's computer goes by many names.  No matter what you lot telephone call information technology, figurer issues take been known to cause P2181.

A4 P2181 Diagnosis:  Conclusion Tree

Before proceeding with diagnosing P2181, brand certain that your A4 has no other diagnostic codes.  Since this code has so many potential causes, another code can help you narrow it downwards considerably.

one. Check the Coolant Level

Make sure that you bank check the coolant level earlier doing annihilation else.  It very well could exist that the coolant is empty if you lot are getting P2181.

If it is empty, you'll need to add together more coolant. Never add together coolant to an overheating engine, every bit that tin crusade a head to crack.  You'll need to find where the leak is coming from.  Starting time past looking under the vehicle and seeing if yous can find whatsoever dripping coolant.  Follow the drips upward to the source.  This can be more challenging than it sounds.

If coolant is total, it's time to test the temperature sending unit.

2. Test the Temperature Sending Unit

Since this code is indicating that the perceived engine temperature is out of range, it would be best to first have a look at the A4's temperature sensor and make sure that information technology is functioning properly.

You tin skip to 3a⬇️ if your A4 is visibly overheating.

If the gauge is reading low, endeavor turning the heater on after the car has been running for a while.  If the air coming out of the vents is not hot at all, that would be a good confirmation that the gauge is reading properly.  Go ahead and jump to 3b⬇️.

Here's how to check to run across if your sending unit has faulty wiring, how to utilize a multimeter with cool/hot water to test the sensor (Youtube).

If the sending unit is bad, replace information technology and should articulate P2181.  If not, permit'south motion on to step 2.

three. Does the Gauge Read also Hot or too Cold?

Ok, now nosotros know the temp gauge is working properly. Permit's continue diagnosing P2181 past determining if the engine is running too hot or too cold.

3a. Too Hot

If the engine is running besides hot, delight jump to pace 4⬇️.

3b. Too Cold

If your A4 is running likewise cold, it is most probable going to exist the thermostat that is at fault.  Replacing the thermostat is usually a pretty straightforward repair.

4.  Thermostat

A typical thermostat

We know from stride 1, that the engine is total of coolant.  This leaves the radiator, h2o pump, or thermostat.  Since the thermostat is easiest to check, we'll start there.

With the engine warm (but not overheating, shut it down before that happens) squeeze the hose going to the water pump from the radiator.  If information technology is limp, motion down to pace half dozen, water pump.

If the hose is hard to squeeze, we know that there is solid water pressure.  The thermostat may not be opening.

Is the heater working?  If the thermostat is all the way closed, information technology shouldn't be.  That would be enough proof that the thermostat is not opening.  For more than see the bad thermostat diagnosis department on this site.

If the heat is working just fine, permit'southward move to step 5.

5. Radiator

If in that location was good water pressure at the radiator hose, and the heater seemed to work fine.  You are going to need to take a look at the radiator.  Here's how to diagnose a bad radiator.(YouTube).

six. Water Pump

Finally, the water pump.  If you've made information technology all the mode downwards here, it's very probable that the water pump is at fault.  Take you heard any squeaking noises coming from the vehicle?

That's a pretty good indication that your A4's water pump is bad.  Here'southward a good h2o pump diagnostic video.  Heres a page on this site about diagnosing a bad water pump in your A4.

7. ECM

If you're looking at your A4's ECM, it's likely that you accept establish cipher visibly wrong with the temperature sending unit, and nothing appears to be wrong with any role of the cooling system.  It could exist the ECM that is at fault, although it's not very probable.

Before touching or because the ECM/PCM, you should still verify that the engine temp is right with a temperature gun, and that the sending unit is working properly.  At that signal yous'd need the PCM refreshed, which your dealer should be able to exercise for you lot.

Audi A4 P2181 Conclusion

Hopefully, this article helped y'all diagnose p2181 in your A4.  It's certainly not the easiest code to effigy out.

DOWNLOAD HERE

2011 Audi A4 Quattro 2.0 T Code P2181

Posted by: jamesmathervenrat.blogspot.com

Share this post