case relearn
#1
case relearn
Anyone ever do this and does it work?
1. Turn off all of the accessories. With the Air temperature sensor and Coolant temperature within 5 degrees (Centigrade) of each other, start the engine and let it idle in Park or Neutral for two minutes.
2. Accelerate the vehicle to 55 mph at part throttle. Cruise at 55 mph for 8- 10 minutes until the engine reaches operating temperature.
3. Cruise at 55 mph for another 5-6 minutes.
4. Decelerate to 45 mph without using the brakes, and maintain 45 mph for 1 minute.
5. Perform 4 deceleration cycles, without using the brakes, of 25 seconds each where no specific speed is necessary. Returning to 45 mph for 15 seconds in between deceleration cycles.
6. Accelerate to 55 mph and cruise for 2 minutes.
7. Stop the vehicle and idle for 2 minutes with the brake applied and the transmission in Drive (automatic trans.) or Neutral (manual trans.) with the clutch depressed
1. Turn off all of the accessories. With the Air temperature sensor and Coolant temperature within 5 degrees (Centigrade) of each other, start the engine and let it idle in Park or Neutral for two minutes.
2. Accelerate the vehicle to 55 mph at part throttle. Cruise at 55 mph for 8- 10 minutes until the engine reaches operating temperature.
3. Cruise at 55 mph for another 5-6 minutes.
4. Decelerate to 45 mph without using the brakes, and maintain 45 mph for 1 minute.
5. Perform 4 deceleration cycles, without using the brakes, of 25 seconds each where no specific speed is necessary. Returning to 45 mph for 15 seconds in between deceleration cycles.
6. Accelerate to 55 mph and cruise for 2 minutes.
7. Stop the vehicle and idle for 2 minutes with the brake applied and the transmission in Drive (automatic trans.) or Neutral (manual trans.) with the clutch depressed
#3
That exact procedure was tossed around the GMT360 forums back when I had my Rainier and had a tuned PCM. The method did not work for them and I doubt it would work here as the relearn procedure with a scantool must be commanded to start and a set procedure followed for a new value to be stored.
#6
You read correctly with regards to a donor PCM. Crankshaft position sensor data is stored in the PCM when the relearn is performed. It remains there until the next relearn overwrites the previous data. If you replace the PCM without performing a relearn, it will use the calibration data from the previous relearn, which is not the correct data for the existing crankshaft position sensor.
Last edited by Captain Hook; 05-15-2016 at 10:23 AM.
#8
Using a capable scan tool, once the year, make, & model is loaded, follow the on-screen safety prompts, (foot on the brake, trans in neutral or park, wheels blocked, etc) bring engine RPM to 4K and the PCM immediately takes control of injectors, engine speed drops, and it's done. Literally less than 2 seconds. An honest shop would charge .5 hours labor or less.
#10
Ask Les Myer, he found a set up that isn't all that expensive. There are always used scan tools on Ebay too. Usually start around $1500, but you need to make sure the software is updated to cover your year of vehicle, and that it has the accessories that you'll need, (cables, connectors, adapters, etc).