What does P1605 mean on a Ford?

P1605. PCM Keep Alive Memory Test Error. Applies to F-150, Mustang, Explorer, Ranger.

What causes P1605 on a Ford?

Internal PCM memory fault Low battery voltage during the memory self-test Corrupted adaptation data Recent failed programming attempt Poor PCM power or ground

How do I fix P1605 on a Ford?

Load-test the battery and verify charging voltage Clear the code and see if it returns on a clean drive cycle Check PCM power and ground integrity Check for a PCM calibration update Replace the PCM if the error persists with good power

Code

P1605

PCM Keep Alive Memory Test Error

Category: Powertrain - Computer and Auxiliary Controls
Severity: Check Engine Light
Applies to: F-150, Mustang, Explorer, Ranger
Related: P0603 Internal Control Module Keep Alive Memory (KAM) Error on OBD Codes List

Findings, check these first

Internal PCM memory fault
Low battery voltage during the memory self-test
Corrupted adaptation data
Recent failed programming attempt
Poor PCM power or ground

Standard procedure

Load-test the battery and verify charging voltage
Clear the code and see if it returns on a clean drive cycle
Check PCM power and ground integrity
Check for a PCM calibration update
Replace the PCM if the error persists with good power

Code lookup

Type a code above, or start from a symptom or a common code.

Press / to jump to the box. Ford-enhanced powertrain, body, chassis and network codes. Generic P0xxx codes live on OBD Codes List.

Sources and review

Review: qualified. Read the source limits below.

OBDII.pro: P1605 Ford definition
live reference page (obdii.pro)
Supports: Ford-family meaning for P1605: Keep Alive Memory Test Failure
Fetched directly. obdii.pro is a publisher independent of the engine-codes family.

Last updated 2026-09-04.

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