P062F: Internal Control Module EEPROM Error
What to do
Mention if the battery has been disconnected, jump started, or gone flat recently — and if a battery was changed, whether the ignition was fully off and the car left to settle first. This memory is written after you switch off, so cutting power too soon corrupts it, and that is one of the commonest causes.
Ask whether any main relay or power supply faults are stored alongside. A relay that drops out too early does this damage every time the car is switched off, so it will happen again after any repair if it is not found.
Expect a rough idle or slightly odd behaviour for a while after a repair, as the module relearns its adaptations. That is normal.
Before agreeing to a replacement module, ask whether the existing one can be reprogrammed. A replacement usually needs coding and immobiliser matching, which is a bigger job.
What this code means
The module's non-volatile memory has failed a read or write check.
EEPROM is where the module keeps what it has learned and what it has been told, and it survives the ignition being switched off — which is exactly what makes this code consequential. It holds fuel trims, throttle and idle adaptations, injector calibration codes, immobiliser data, the vehicle's coding and the odometer on some vehicles.
So the risk is not merely that the module misbehaves. It is that the vehicle forgets who it is. Lost adaptations produce rough idle and poor driveability until they relearn; lost immobiliser or coding data can leave a car that will not start and needs dealer-level programming to recover.
The most important cause is preventable and worth understanding, because it connects this code to others in this block. EEPROM is written during the module's shutdown routine, after the ignition is switched off. If power is removed before that finishes, the write is interrupted mid-cell — which corrupts memory rather than simply failing to save.
Which is why a failing main relay, a bad earth, or disconnecting the battery while the module is still awake all cause this. Look for a relay code stored alongside — a relay dropping out too early is a documented route here, and it will corrupt the memory again after any repair if it is not fixed.
Have the battery and charging system checked, since a voltage sag during a write does the same damage.
Likely causes
Start here
- Voltage collapse during memory write · moderate
- Degraded module memory · specialist
- Low system voltage · easy
Less common
- Failed software update · specialist
- Water ingress into module · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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