P0502 DTC after first run...
Thread Starter
TECH Apprentice
Joined: Nov 2001
Posts: 387
Likes: 0
From: South Elgin, IL
P0502 DTC after first run... Took my Z to the track for the first time after the ST-3800 install. Put it D for the first burn-out to heat the Nitto's and made my run. Made a second run the same way (hot-lap).
Someone mentioned about doing burn-outs in 2nd gear. OK, so I do it. No problem. I make my run and hot lap back into the water box. I put the car in second, mash the pedal, the converter stalls but now the Nitto's don't even spin up. I line up and make my run anyway only to find out the car is stuck in 2nd. No SES light. I ATAP it and find the DTC code P0502.
I cleared the code and let the car cool down for 15 minutes or so. First run goes well, second run does the same exact thing. I cleared the code once again and drive home without any problems.
Found this info on P0502:
P0502 Vehicle Speed Sensor Circuit--Low Input
DTC P0502 stores in PCM history
The PCM commands second gear only
The PCM commands maximum line pressure
The PCM freezes shift adapts from being updated
The PCM inhibits TCC engagement
Did the burn-outs in 2nd cause the problem? Anybody else ever get this code? First two times through the water box I kept it in D and I didn't get any codes the second burn-out.
Someone mentioned about doing burn-outs in 2nd gear. OK, so I do it. No problem. I make my run and hot lap back into the water box. I put the car in second, mash the pedal, the converter stalls but now the Nitto's don't even spin up. I line up and make my run anyway only to find out the car is stuck in 2nd. No SES light. I ATAP it and find the DTC code P0502.
I cleared the code and let the car cool down for 15 minutes or so. First run goes well, second run does the same exact thing. I cleared the code once again and drive home without any problems.
Found this info on P0502:
P0502 Vehicle Speed Sensor Circuit--Low Input
DTC P0502 stores in PCM history
The PCM commands second gear only
The PCM commands maximum line pressure
The PCM freezes shift adapts from being updated
The PCM inhibits TCC engagement
Did the burn-outs in 2nd cause the problem? Anybody else ever get this code? First two times through the water box I kept it in D and I didn't get any codes the second burn-out.
Re: P0502 DTC after first run... That's wierd. As you know, placing the selector in 2 starts the car in 2nd and not 1st. (this applies to '00 and up F-bodies). Maybe for some reason, your computer didn't like all the rpm in 2nd gear with the front wheels not moving. Can't be sure. Wouldn't hurt to check the speed sensor too. It's at the rear of the tranny, on the passenger side.
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2023 Corvette 3LT Z51 soon to be modified.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
Re: P0502 DTC after first run... I got that 502 code yesterday at the track.I have never set that one before in over 300 passes.
I was trying out a new tire,MTET Drag 26/9.5/15 and figured it would be a bit taller than my old ET Streets,WRONG.The motor crashed the rev limiter hard on the 2-3 shift and it would not go into third.
I thought the trans was toasted but ATap showed that 502 code.When I cleared it and reset my RPM limit to 6600 with HPP it was fine.
I made a pass and forgot to shift it to OD after the burnout,crashed the limiter and it set the 502 again.
OK,I know this is a bit long but I think you hit your limiter hard on the burnout and set the 502.I have never set that code on a slight touch on the limiter.
The track was closing and I had no time to clear code and make another pass.The trans seems to be shifting great and pulled 1.58 60s on those non 2/3shift passes.
Where do you have your rev limit set?Have you changed shift points? I hope this helps a bit.
I was trying out a new tire,MTET Drag 26/9.5/15 and figured it would be a bit taller than my old ET Streets,WRONG.The motor crashed the rev limiter hard on the 2-3 shift and it would not go into third.
I thought the trans was toasted but ATap showed that 502 code.When I cleared it and reset my RPM limit to 6600 with HPP it was fine.
I made a pass and forgot to shift it to OD after the burnout,crashed the limiter and it set the 502 again.
OK,I know this is a bit long but I think you hit your limiter hard on the burnout and set the 502.I have never set that code on a slight touch on the limiter.
The track was closing and I had no time to clear code and make another pass.The trans seems to be shifting great and pulled 1.58 60s on those non 2/3shift passes.
Where do you have your rev limit set?Have you changed shift points? I hope this helps a bit.
Thread Starter
TECH Apprentice
Joined: Nov 2001
Posts: 387
Likes: 0
From: South Elgin, IL
Re: P0502 DTC after first run... I didn't hit the limiter on the burnout but it all makes sense now.
My first run I would hit the limiter on the 2-3 shift so I bet that set the code. That's why I had the issue only on my second consecutive runs. I would pit, reset the code and have one good run.
I'm using all the stock settings since I have an '02 and there's nothing out yet for them. I have a PCM with '00 code coming from Ken K. and LS1 Edit in two weeks. That should take care of it.
My first run I would hit the limiter on the 2-3 shift so I bet that set the code. That's why I had the issue only on my second consecutive runs. I would pit, reset the code and have one good run.
I'm using all the stock settings since I have an '02 and there's nothing out yet for them. I have a PCM with '00 code coming from Ken K. and LS1 Edit in two weeks. That should take care of it.
