Toyota corolla is a car brand cumulative sales champion of more than 36 million units in the world, key fob from 4C chip to 4D and G chip. Here to share some methods for 4C chip key, including add keys, all key lost programming and reset immobilizer.
Before June 2005, the immobilizer box of 4C chip was integrated into the engine ECU, use European style anti-theft system, no immobilizer box, called “old Corolla”, after June 2005, there is a separate immobilizer box with a US style anti-theft system, called “ex new Corolla”.
Although they all use 4C chips, but programming method is quite different. Following details are for old corolla and ex new corolla.
Old corolla (before June 2005) adding keys, all key lost programming, reset immobilizer.
Method 1: add keys manual
1. The master key is required. All doors closed, insert master key quick turn on and off ignition five times, (turn on and turn off is one time) and finally keep OFF.
2. The main door shall be opened and closed for 6 times and finally keep closed.
3. Pull out the key, insert the new key and turn ignition on for one minute.
4. security light off, that is add key successfully.
Method 2: all key lost, write key to start
If master key is lost, manual add keys is not available, have to write the key to start. For old corolla, have to disassemble the engine ECU which located under the passengener's glove compartment, open ECU and find the 8-pin EEPROM chip 93C56 near CPU.
Step 1: read data with key programmer like Yanhua key master, CG100 and VVDI Prog etc.
Step 2: read a 4C chip with code reader like mini 900, for example get a code 70 88 CA 0A, then trans posited the chip data into 88 70 0A CA and manual write it to EEPROM date as the first master key, check red in below photo. Make the second master key use the same way, read a 4C chip and get code 9F 8A CA 0A, then trans posited the chip data into 8A 9F 0A CA and write it to eeprom data as second key, check blue in below photo. Third key is same steps check yellow in photo. Save the data.
Step 3: Write modified data in step 2 to EEPROM chip with Yanhua key mater, CG100 and VVDI Prog etc. Solder the eeprom back to ECU, assemble the engine ECU to car. Finish.
Method 3: Reset immobilizer
What if no chip cloner like mini 900 etc? Reset initialization data on the car to learn new key,read data of 8-pin EEPROM chip 93C56 data, then modify like this: replace the bytes of red underline as same as photo, remaining bytes replace 0。
Write the data back to EEPROM, assemble the engine ECU to car, Insert the master key to ignition and turn it on, wait 10 seconds and turn off, replace second key and turn on, wait 10 seconds and turn off, then next key.
How to active remote key fob?
Step 1: open the driver’s door, quick switch ignition five times, security light will keep on.
Step 2: Push the key button, the light will be off.
Step 3. Push key button again and the security light is on again, that is one key fob has been programmed successfully.
EX new corolla (after June 2005) add keys, all key lost programming, reset immobilizer.
Method 1: manual add key, master key is required.
Step 1: close all door, insert master key to ignition, do not turn on.
Step 2: quickly step on the accelerator five times, (notice the gas pedal as far as possible more than half), and then hit the brake six times.
Step 3: replace a new key to ignition, do not turn on, then step on the accelerator one time.
Step 4: security light will be off around 45s, that is keys successfully added.
Method 2: all key lost, write key to start
Step 1: Remove the immobilizer box which placed in right above the glove box, open it and find 8-pin EEPROM chip 93C66, Read the data with key programmer like Yanhua key master, vvdi key prog. Etc.
Step 2: read a 4C chip with code reader like mini 900, for example get a code 70 88 CA 0A in below photo, then trans posited the chip data into 88 70 0A CA and manual write it to EEPROM date as the first master key, ensure as same as red position in below photo. Make the second master key use the same way, read a 4C chip and get code 9F 8A CA 0A, then trans posited the chip data into 8A 9F 0A CA and write it to eeprom data as second key, ensure as same as blue position in below photo. Third key is same steps, check yellow in photo.
Step 3: Write the data back to EEPROM, assemble the immo box to car.
Method 3: Reset immobilizer box
Modify the eeprom data read from chip 93C66 as same as below photo, retain bytes with red underline, other letters all replace with F. Save the file.
Write the data back to EEPROM, assemble immo box back to car. Insert the master key to ignition and turn on, wait 10 seconds and turn off, replace second key and turn on, wait 10 seconds and turn off, then next key. The learning interval for each key should not exceed 10 seconds. If it cannot start the car, do the synchronize process, with the engine off and the key in “off” position, use Short cable or paper clip to connect the 4th pin and 13th pin of the OBD and turn ON the ignition, many lights in Dash panel will start flashing, it means the process is going smoothly. Wait for 45 minutes, turn off the ignition and remove the line. Finish.
How to activate EX new corolla key fob？
1. Close all doors, insert the key into ignition, do not turn on.
2. Then open and close the door three times. (Open - close - open)
3. Turn the ingnition on and off five times(on-off-on-off-on-off), emergency flasher will be flashing
4. Push the lock and unlock buttons of key fob at the same time, then the emergency flasher will flash one more, that is key fob is activated.
Important notice: do not wait too long when turn on and off the ignition and open close the doors.
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