What does it mean?
P1695 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: EEPROM Error . This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms
- MIL on and the code returns straight after clearing
- Learned values lost: rough idle, poor shift quality, immobiliser or key recognition problems
- Adaptations reset repeatedly, so the vehicle appears to relearn every time it starts
- Scan tool communication drops, or the module reports invalid configuration data
- Vehicle may not crank at all if immobiliser data is affected
- Settings such as idle speed or fuel trim behaving unpredictably
Likely causes
- Corrupted stored data after a voltage drop or an interrupted write cycle
- Battery disconnected, jump started or charged while the module was powered and writing
- Interrupted or failed software programming session
- Weak or failing battery causing repeated low-voltage resets of the module
- Moisture or corrosion inside the module housing damaging the memory circuit
- Poor module ground or power feed letting the supply voltage sag under load
- Genuine internal failure of the memory chip
How to fix it
- Test the battery and charging system properly, because unstable supply is the usual root cause
- Check the module power feeds and ground circuits for voltage drop under load
- Inspect the module and its connectors for water intrusion, corrosion and heat damage
- Clear the code and complete a full drive cycle to see whether it was a stored one-time event
- Attempt a reprogramming or recalibration of the module with a stable power supply connected to the vehicle
- Redo any configuration, coding or key learning the module requires after a successful reflash
- Replace and program the module if the memory error persists after a clean reprogramming attempt