How to Install new custom tuned ecm(s) 1999-2007 Classic:

Disconnect the negative battery terminal before removing the PCM.  The PCM on 99+ Trucks is located under the hood on the driver side, next to and below the battery. Remove the PCM cover by pulling outward on the cover to clear the holding tabs. Use a 7mm socket and ratchet to remove the PCM connector bolts.  Slide the PCM out of its plastic case.

If the orange seals are stuck to the pcm, simply remove them and place them over the pcm harness connectors.

Helpful hints and tips:

Pass-key relearn procedure.  If your truck/car doesn’t start, perform the vats relearn procedure.  A copy of the procedure can be obtained at http://www.nelsonperformance.com/security-relearn.

Crankshaft relearn may need to be performed. The procedure requires the use of a TechII/Genisys or similar handheld unit capable of doing the relearn.  If you need a copy of how the procedure is performed please email info@nelsonperformance.com

A rough idle can occur because the idle has not been learned yet.  An idle relearn is necessary.  Read the following information carefully after installing the PCM for a quick relearn procedure. To fix–simply start the vehicle with 10-15% throttle. Allow to idle. When the idle is stable, put the vehicle in gear with the brake applied. Allow for the idle to stabilize for 20-30 seconds. Return to park. Shut off and re-start to see if the idle is now stable.  When tuning for a high-performance cam, the idle relearn can take several cycles to completely fix itself.  Driving the vehicle several miles in stop and go conditions will also help.

SES or error codes: Your local auto store may provide this service for free.  In the event your vehicle does have a SES code, please call us immediately 210-626-0278 or send an email to info@nelsonperformance.com.