85 with a check engine light and code 21
Thread Starter
Heel & Toe
Joined: Nov 2003
Posts: 18
Likes: 0
From: Lodi Ohio
85 with a check engine light and code 21
Since my last autocross my 85 has been throwing a code 21 and the idle goes up to 1100 until I reset the PCM by disconnecting the battery. It doesn't happen immediately and sometimes it does it at idle or others I have to drive it a few miles before the SES light goes on. Code 21 is supposed to be high power steering pressure.
I can't find a sensor or any other wiring going to the steering components so it can be looked at. My question is there a sensor and wiring going to the PCM and can it be disconnected to eliminate the code and light? Any response would be appreciated..Expo
I can't find a sensor or any other wiring going to the steering components so it can be looked at. My question is there a sensor and wiring going to the PCM and can it be disconnected to eliminate the code and light? Any response would be appreciated..Expo
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Yes, a code 21 on a 85 is the TPS. This means the ECM has seen a voltage outside it's programmed limits. Not necessarily that the TPS is bad but could me misadjusted, poor connection, or open/grounded circuit. I would try the TPS steps below and just for fun you might want to clean the IAC and TB. Never hurts to remove the carbon.
https://www.corvetteforum.com/techti...=195&TopicID=2
https://www.corvetteforum.com/techti...D=55&TopicID=2
https://www.corvetteforum.com/techti...=195&TopicID=2
https://www.corvetteforum.com/techti...D=55&TopicID=2
