Frequently Asked Questions.

When retrofitting an LS engine into a Chevy OBS (Old Body Style) truck, one common issue is the incompatibility of the factory gauges with the LS PCM (Powertrain Control Module) signals. The primary reason for this is that the original gauges were designed to work with analog signals from the pre-OBD II systems, while the LS PCM uses digital signals and communicates differently. This fundamental difference in signal type means that the factory gauges do not receive the appropriate inputs to display accurate readings for parameters like speed, temperature, and fuel level.

Another contributing factor is the difference in wiring and sensor compatibility. The original sensors in OBS trucks typically output voltage or resistance signals, while the LS PCM may use different protocols or outputs. For example, the speedometer may rely on a mechanical drive or a simple voltage signal, whereas the LS system may output a digital signal that the stock speedometer cannot interpret. This disconnect requires additional components or modifications to bridge the gap between the two systems.

Lastly, the calibration of the gauges poses another challenge. Even if the gauges could be made to receive the correct signals, the scaling and calibration might not match the LS engine’s outputs. The factory gauges are calibrated for the original engine's specifications, which can differ significantly from those of the LS engine. This necessitates either aftermarket solutions that can interpret and convert the LS signals correctly or custom gauge setups that can be calibrated to reflect the new engine’s performance accurately. Without addressing these issues, achieving accurate and functional gauge readings becomes a significant hurdle in the LS swap process.

Yes, the gauges can  function and there is a write up on lt1swap.com.  He goes over the additional steps.

We accept all major credit cards and PayPal/Money orders.  I will send an invoice to your email when the harness is complete.