99 K1500 engine swap 5.0 to 5.7

[bwhastings]

Hi guys

I just completed a 5.0 to 5.7 swap on my sons truck it’s running great except now the check engine light came on there’s 2 codes it’s showing B2960 I checked it and says passlock the computer I have says it’s wrong but ok (whatever that means) and the other is C0238 speed sensor. I was going to change the speed sensor out but I’m worried its not going to fix the issue. Could these codes be due to the engine swap. I did not change the PCM

 

[Schurkey]

1. Clear the codes, see what comes back. A code that doesn't return can be ignored.

2. What does the scan tool show for vehicle speed? Is it reasonable, or obviously "off" from true speed? Does the scan tool not show vehicle speed at all? I don't know how swapping engines can cause a vehicle-speed sensor code, since you didn't swap the transfer case--and that's where the VSS is located. Did you fail to support the transmission when the engine was out, and so the trans/transfer case sagged and pulled on the harness or crushed the sensor somehow?

3. Download the service manual for your vehicle from the links posted on this web site. Follow the official diagnostic procedure for each active code.