D4 light on dash will not go out, at 1,800 RPMs it will, also shuts off

Hi, I did what you said and jumped the connector, the d4 turned on and did not blink. Check engine light blink 15 and 4. I turned the key off and back on no d4, same CEL 15, 4. I repeated this a few times everything came out the same the only weird thing is the d4 only came on and stayed on every other time. ( On - off - on - off - on - off - etc. ) The codes came every time 15, 4.

I cannot drive it that would require holding above 1,800 RPMs. The car starts up when it's cold maintains start up idle speed I can turn it on and off runs just fine, I can even drive it. When it gets to running temperature it shuts off and will not start up entitles it cools down. If I watch the temperature gauge and keep the RPMs at 1,800 I can reach running temperature and the car will keep running. If I take my foot off the gas it will stop running and will not start until cooled. I noticed when I was checking to see if I could turn it off and on when it was cold that the d4 light would be on every other time (on d4 light, off/on no d4 light, off/ on d4 light, off/ on d4 light, off/ on no d4 light, off/ etc.), I put my jumper wire in the connector to get my codes my check engine light flashed 15 and 4 / shift panel light solid d4 no flashing. I turned it off and back on check engine light flashed 15 and 4 /shift panel light no d4, Every time I turn the key on the check engine light cel) flash 15 and 4 / Every other time the shift dash panel light d4 would be on and not flash. (Turn on cel flash 15 and 4, d4 solid light, / turn off, / turn on, / cel flash 15 and 4. No d4 light./ Turn off, / turn on, / cel flash 15 and 4. Solid d4 light, / turn off, / turn on, / cel flash 15 and 4. No d4 light this pattern will repeat with every on, / off, / on. I let it cool down and started it up before it reached reached running temperature I turn the idle screw up, when the fans came on it was still running I turn the idle screw until it was running at about idle (800 - 900 RPMs] steady no fluttering. While still in the engine compartment I grabbed throttle and opened it up and let it return to idle did this 3 or 4 times and it kept running. I get in the driver seat (I forgot to tell you I cleared the codes) the d4 light is still on / no check engine light I step on the gas pedal few times it revs up, returns to idle and keeps running. I put it in reverse and sit there a little bit, it still running. I start to back out makes it 3 feet it shuts off check engine light came on. I think I check the codes and they were the same but I might not have I was upset and it was raining pretty hard.