Basic OBD Tuning Procedure
Here are some pointers, or consider it a general guide to calibrating an ECU correctly and safely through the OBD port.
Do not try to cut corners, rush or cheat the job
Remember to choose the right tool for the specific vehicle in hand.
- Check for fluid or air leaks
- Check that everything physically looks correct under the bonnet
- check for 3rd party radio/Sat Navs installations and insurance trackers. These are usually piggy backed onto the CAN-BUS and can interfere with vehicles that communicate on the network. These are known to cause communication issues with OBD flash tools.
- Once again, its all about covering yourself should something arise during or after the tune due to poor maintenance.
- Check the fluid levels, you do not want to be tuning the car if there is no oil or water in it!
- If you spot anything make the customer aware that you see a problem, that way you are covered should any problem arise later on.
- Check the OBD port is in good condition and look to make sure it is the original plug. There are afermarket devices that connect via the OBD port and can be disguised very well. This will in turn can cause a manner of problems should a device be fitted, like unable to read/write the ecu correctly.
- Check to see if it has a tuning box fitted in the engine bay. By installing a tuned file with a tuning box fitted could potentially lead to engine damage. By bending signals on already raised limits will push the engine past its safe working parameters.
- ALWAYS BE PREPARED TO WALK AWAY FROM A JOB IF THE VEHICLE HAS FAULTS. This can cause time wasting at your end by having to revisit a job, and also cost us valuable time trying to repair something that isn't caused by a calibration error. THIS IS NOT A FAULT WORK-AROUND SYSTEM
Test Drive the Vehicle
- Check for any warning light's illuminated on the dash.
- Listen for any noises coming from the engine. Ie, boost leaks, knocking, rattles etc etc.
- Make sure there is no lack of power or any running issue's.
- Get a general feeling for the vehicle.
Do not skip this step!
- If there DTCs stored in the vehicle then it will be down to you to decide whether to proceed to the next step.
- Clear all DTCs in the control module. Rescan the system and again check for Present DTCs. If the system clears down correctly, then a Full drive cycle must be completed to ensure all readiness checks are completed. This will ensure all emission systems are functioning correctly and you are safe to tune.
- For European model manufacturers, We recommend the AUTOLOGIC ASSISTPLUS  for diagnostics, resets and adaptations. This is the ultimate tool for chiptuning.
Reading the Original Calibration
Voltage is key when flashing an ECU so ensure that the vehicle has plenty of it.
- The recommended voltage for reprogramming an ECU is a stable 12.5v - 13.5v. This procedure is industry standard across all vehicle manufacturers when flashing dealer updates to vehicles. It is recommended to use a supply such as the Snap on EEBC500  as this can can supply a stable supply up to 60amps constant.
- Plug your Flash tool into the OBD port and ensure it is fully inserted. Ensure the tool software is reading battery voltage.
- It is always recommended to use a charger for your laptop. This is in case of battery failure or the read time exceeding the battery life.
- Close any other programs running in the background. This ensures full processing power and RAM availability.
- Rest the pc in a secure place in the vehicle where the data cable cannot be disturbed during the programming.
- It is always a good idea to turn off all loads in the vehicle, especially high load items such as heater fans and lights
- Now follow the on screen prompts for reading that particular vehicle in the tool software.
- NOT ALL TOOLS GIVE ON SCREEN INSTRUCTIONS. KESS V2 WILL PROMPT IGNITION CYCLING. CMD/MPPS DOES NOT PROMPT. AFTER EVERY PROCEDURE THE IGNTION MUST BE CYCLED.
- KEY ON
- ID THE ECU
- KEY OFF
- KEY ON
- READ ECU
- KEY OFF
- BUILD FILE
- KEY ON
- ID ECU TO DOUBLE CHECK PROTOCOL
- KEY OFF
- KEY ON
- WRITE MOD FILE
- KEY OFF
- WAIT 60 SECS FOR ECU TO POWER LATCH
- START ENGINE
Always ID the ECU first as this will give good indication that you have selected the correct ECU and that you have good communications.
- If you need help or advice on how to enable full ignition on vehicles such as BMW or Renault cars, Please see our specific guide for these vehicles.
- Once the vehicle has read the Ecu successfully, you are now ready to build a calibration.
Building your tune
- Upload original file
- Build Calibration including deactivations
- Download Modified Calibration
- See here for build instructions: How To Use The PCW Website
Writing the modified calibration file
- If you have removed your pc from the vehicle, ensure that data cables are fully inserted into the port and the laptop.
- Make sure the power supply is turned on and you have good voltage. REMEMBER VOLTAGE IS KING Especially when writing back an ECU.
- Reopen flash software and carry out an ID to ensure good communication.
- Once you are happy, select the modified file and write it into the Ecu.
- Be-careful not to disturb the pc or the vehicle during the programming. This is paramount as this could potentially damage the ECU permanantly.
- Once the tool has successfully finished programming the ECU, Switch the ignition off for at least one minute. This allows the ECU to power latch.
- Disconnect all equipment from vehicle. Some vehicles that communicate on CAN-BUS have been know to do some strange things while the flash tool is still connected to the OBD port.
- Start vehicle and allow to idle for 2 minutes to allow the ecu to start its readiness checks.
- Test drive the vehicle at various speeds and loads to ensure calibration is as it should be.
- Ensure vehicle has gained expected performance if a performance calibration has been installed.
- After the road test, Diagnostically check the vehicle again to make sure all is clear.
- Now you are ready to hand the vehicle back to the customer, knowing the job is 100% complete.