Back to 2003 Lexus LS 430

2003 LEXUS LS 430

4.3L V8RWDAUTOMATICgas
Repairs0Labor591Torque5693Fluid7DTC734Battery0Maintenance0Recalls0
P1605high severityPowertrain

Knock Control CPU Malfunction

on 2003 Lexus LS 430 4.3L V8 · RWD

What this code means

The ECM detected a communication failure with the knock control CPU.

Symptoms

  • CEL
  • Engine knock under load
  • Reduced performance
  • Timing retarded to safe value

Common causes

  • Faulty knock CPU in ECM
  • Damaged knock sensor wiring
  • Faulty knock sensor
  • Poor connections

Diagnostic steps

  1. Test knock sensor
  2. Inspect wiring harness
  3. Check ECM operation
  4. Monitor knock retard

Repair notes

Replace knock sensor or ECM.

Other Powertrain codes on this vehicle

Building an app?
Free API access to all this data — 50 requests/day, no card required.
Get an API key →
Run a shop?
Manage repairs, estimates, and customers with ShopBase — $249/mo, all features included.
Try ShopBase →