2008 Lexus IS FFACTORY OEM SERVICE PROCEDURE

DTC P1607 Cruise Control Input Processor: Description

The ECM continuously monitors its main and sub CPUs. This self-check ensures that the ECM is functioning properly If outputs from the CPUs are different and deviate from the standard, the ECM will illuminate the MIL and set a DTC immediately

DTC DETECTION CONDITION CHART

DTC No. DTC Detection Condition Trouble Area
P1607 ECM CPUs malfunction (1 trip detection logic) ECM
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.