p1518 TAC Module serial data circuit

[ttls1]

Hi, I have a small issue with my conversion. It's running 2003 Silverado 1MB PCM and TAC and will throw a P1518 code if the ignition key is cycled on, off and on quicker than 3 seconds. I believe the code is thrown due to the fact the TAC needs to power up a split second after the PCM. I have tried putting a load on the TAC supply to drain the power once the key is off but it made no difference. It appears the TAC is not powering off quick enough. I have the TAC 12v power wired as per the Silverado drawing, connected to the PCM Switched 12v supply. I am running COS V3. Just wondering if anyone else has seen this problem? I have tried a different PCM and no difference. Any info would be much appreciated.

[megadeus]

What year gas pedal and tac module is installed? I had issues with a 2003 pcm talking to a 2006 tac module setting a p1518.

[ttls1]

It's all from the same donor vehicle. Everything works fine and I have been driving it for 6 months but just can't figure out this small issue.

[ttls1]

Sorry to dig this 5 yr old thread back up but I never actually got this issue sorted and have just lived with it. Just wondering if there is a way to permanently disable the P1518 code with patch or something?? Setting it to not report in the DTC and MIL has no effect. It only shows up if the ignition is turned off and on quickly like if it stalls and I try a quick restart. Apart from that it never gives an issue and the car drives fine. I just want the PCM to never flag it if this is somehow possible. Cheers.

[joecar]

Thanks for the feedback.