P0221 - Throttle Position Sensor B

A6 All/ S6 All
#1

Engine:
P1564 - Throttle Actuator (J338), Under-Voltage during Basic Setting
P0327 - Knock Sensor 1 (G61), Circuit Low Input
P0221 - Throttle Position Sensor B (G188), Circuit Range / Performance

I got an EPC fault today after many weeks of clean driving.

At first, I was getting them on cold starts in the deep cold of winter. We thought it might be a battery thing, but we couldn’t find any definitive issue with battery drains. Then we cleaned all the connectors and it went away—but the weather also warmed up. However, a few weeks/month later it popped up again, so I swapped throttle bodies. And all was good again for a few more weeks—until a long road trip today.

Any ideas?

#2

Almost seems like a loose wire connection at the throttle body to me. Might explain why it worked for a few weeks after you replaced the throttle body, then started acting up again. I’d try cleaning the contacts with some alcohol if you can, and see if that changes anything

#3

It could be. I drove 300+ KM today in 12C weather and no problems at all. Can you order new connectors to the TB and re-pin?

BUT during the winter my mech said that he was able to trigger the fault by wiggling a wire at the ECU. He said he cleaned the connection, but the problem has been so intermittent it’s hard to track down. The only difference is that this last time I was not able to keep the code clear until the next morning.

#4

Can anyone help me find a part number for the throttle body connectors? I know the “A” side has a broken clip and is held closed with the aid of a zip tie. I might try to replace both.

#5

I tried to look for the actuall connector part number. I can’t find any for the connectors.

Lets play "Fix it or Scrap it"
#6

FYI. Still getting these occasional faults, but it must be wiring or the connector. My mechanic traced J338 as the B sensor on the passenger side TB. (Not the B throttle body) So we were looking in the wrong side.

Looking for a new 6-pin connector. Does anyone have a part number?

#7

Did you get this solved? If not - check out my thread on throttle body connectors.

#8

Thanks. I did get it fixed and then promptly put the car on a boat for Malaysia. I think we cleaned the contacts and then used cable ties to lock them in place.

I’ll get the car back at the end of Sep and if it’s still a problem, I’ll probably replace the connectors. Thanks for checking.

#9

If you can post the actual connector part numbers. I think that was the only thing missing from chevdogs post.