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Home/DTC Codes/Lincoln/LS/2000-2006 3.9L V8/P1605
P1605

PCM Keep Alive Memory Test Failure

2000-2006 Lincoln LS 3.9L V8

Moderate SeverityPowertrain

Description

The PCM Keep Alive Memory self-test has failed. The PCM cannot properly store or retrieve adaptive learning values from its KAM.

Symptoms

  • Check Engine Light
  • PCM defaults to base calibration
  • Rough idle initially
  • Harsh transmission shifts

Common Causes

  • KAM circuit voltage issue
  • Faulty KAM fuse or relay
  • PCM internal failure
  • Battery cable issue

Diagnostic Steps

  1. Check KAM fuse and relay
  2. Test KAM circuit voltage at PCM connector
  3. Check battery and alternator
  4. Clear code and retest — if recurring, suspect PCM failure

Repair Notes

Check KAM circuit power supply. Replace fuse if blown. If KAM circuit is OK, PCM may need replacement.

Related Codes

P1600PCM Battery Direct Power CircuitP1600PCM Battery Direct Power CircuitP1600Loss of KAM Power — Open CircuitP1600PCM Battery Direct Power CircuitP1600PCM Battery Direct Power CircuitP1600PCM Battery Direct Power CircuitP1600PCM Battery Direct Power CircuitP1600ECM Battery Backup CircuitP1600PCM Battery Direct Power CircuitP1600Loss of KAM Power Circuit OpenP1600Loss of KAM Power — Open CircuitP1600ECM Battery Backup CircuitP1600PCM Battery Direct Power CircuitP1600ECM Battery Backup CircuitP1600Loss of KAM Power — Open CircuitP1633ECM Malfunction ETCS CircuitP1633Keep Alive Power Voltage Too LowP1633Keep Alive Power Voltage Too LowP1633Keep Alive Power Voltage Too LowP1633Ignition Supply Power Circuit Low VoltageP1633Ignition Supply Power Circuit Low VoltageP1633Ignition Supply Power Circuit Low VoltageP1633Ignition Supply Power Circuit Low VoltageP1633Ignition Supply Power Circuit Low VoltageP1633Ignition Supply Power Circuit Low VoltageP1633Ignition Supply Power Circuit Low VoltageP1633Ignition Supply Power Circuit Low VoltageP1633ECM Malfunction ETCS CircuitP1633KAM Voltage Too LowP1633ECM Malfunction ETCS Circuit

Other Powertrain Codes

P1605 on Other Vehicles

Lincoln Aviator

2003-2005 4.6L V8

Lincoln Aviator

2003-2005 4.6L V8 DOHC

Lincoln Aviator

2020-2024 3.0L Twin-Turbo V6

Lincoln Aviator

2020-2024 3.0L V6 Twin Turbo

Lincoln Aviator Grand Touring

2020-2024 3.0L Twin Turbo V6 PHEV

Lincoln Aviator Grand Touring

2020-2024 3.0L Twin-Turbo V6 Hybrid

Lincoln Aviator Grand Touring

2020-2024 3.0L V6 Twin Turbo Hybrid

Lincoln Blackwood

2002-2002 5.4L V8

Common Questions

What does code P1605 mean on a 2000-2006 Lincoln LS?

P1605 stands for "PCM Keep Alive Memory Test Failure". The PCM Keep Alive Memory self-test has failed. The PCM cannot properly store or retrieve adaptive learning values from its KAM.

What are the symptoms of P1605 on a Lincoln LS?

Common symptoms of P1605 include: Check Engine Light, PCM defaults to base calibration, Rough idle initially, Harsh transmission shifts.

What causes P1605 on a 2000-2006 Lincoln LS?

Common causes of P1605 include: KAM circuit voltage issue, Faulty KAM fuse or relay, PCM internal failure, Battery cable issue.

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