P1605high severityPowertrain
Knock Control CPU Malfunction
on 1996 Lexus LS 400 4.0L 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
- Test knock sensor
- Inspect wiring harness
- Check ECM operation
- Monitor knock retard
Repair notes
Replace knock sensor or ECM.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1