DME Code 8121

[barry1@nine-eleven.com]

We have a check engine light on and a code 8121 on an '08 Cayenne S.. We cannot find any information on this code.

Thanks in advance for the help.

Barry

Edited May 28, 2013 by barry1@nine-eleven.com

[Loren]

:welcome:

P8121 Cooling System Performance

Check your coolant levels. Did the coolant light come on?

[jbautista]

is the code 1901 related to the same system?? i have them both 8121 and 1901 with description.

[Loren]

No, totally unrelated - 1901 is a seat problem.

Fault code 1901 Motor for vertical lumbar adjustment

Possible causes of fault- No vertical lumbar adjustment possible (Electrical fault in electric circuit)- No vertical lumbar adjustment possible (short circuit to B+)- No vertical lumbar adjustment possible (short circuit to ground)- No vertical lumbar adjustment possible (open circuit)

[tedd9146!]

Loren...

2009 Cayenne...

I have a similar recurring Check Engine light and am getting the 8121 code. Hearing something about an issue with the thermostats....have you heard anything that way? New thermostat cure the problem, yes or no? Told today by friend with shop, labor code calls for 7.5 hrs on replace! Will probably do that with 60K service...and try to get more info from dealer!

Thanks for all the great info!!

Edited November 19, 2013 by tedd9146!

[Loren]

There is a TSB for new sealing rings for the on the intake socket of the coolant regulator housing. But I think that assumes there is a leak.

But I would look for coolant leaks and coolant in the oil (or oil in the coolant) - first.

[tedd9146!]

There is a TSB for new sealing rings for the on the intake socket of the coolant regulator housing. But I think that assumes there is a leak.

But I would look for coolant leaks and coolant in the oil (or oil in the coolant) - first.

Thanks Loren...will check that out! You're a gem!

[Doug_B_928]

I've been getting the check engine light in my 08 Cayenne S with P8121 "Implausible Signal." I clear it and it comes back in a few days. After just now finding this thread, I'll check the coolant level. I'm just wondering if any of you who posted here, now that some time has passed, have any updates on what the problem was and solutions.