P1681
Control Module Not Programmed
Severity
🔴 HighCan you drive?
Do not drive — repair immediately
Approx. repair cost
~$556 (est.)
Symptoms
- Engine won't start
- Check Engine Light Is On
- Loss of engine power
- Incorrect transmission operation
- Malfunctions of the car's electronic systems
Causes
- Replaced ECU without programming
- ECU software failure
- Problems with ECU power supply
- Unsuccessful attempt at flashing
- ECU memory damage
How to Fix
- Check battery voltage and ECU power supply circuit
- Read all error codes using a diagnostic scanner
- Check the repair history to see if the ECU needs to be replaced
- Reprogram the ECU at an authorized dealer
- If necessary, replace the ECU