Engine-Codes - Toyota - P0604 2002 TOYOTA HIGHLANDER

P0604 2002 TOYOTA HIGHLANDER - Internal Control Module Random Access Memory Error

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

P0604 2002 TOYOTA HIGHLANDER Possible Causes

  • Faulty Engine Control Module (ECM)
  • Engine Control Module (ECM) Harness power supply circuit is open or shorted
  • Engine Control Module (ECM) Programming

How is the P0604 2002 TOYOTA HIGHLANDER code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

Tech Notes

Check the ECM fuse, if fuse is OK try erasing the code first and if the code comes back you may have to reprogram or replaced the ECM.

What is the cost to diagnose the P0604 2002 TOYOTA HIGHLANDER code

Labor: 1.0

The cost to diagnose the P0604 2002 TOYOTA HIGHLANDER code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.
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When is the code detected?

Indicates the ECM has experienced an internal memory fault.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Engine may not start

P0604 2002 TOYOTA HIGHLANDER Meaning

The Engine Control Module (ECM) continuously monitors its internal memory status, internal circuits, and output signals to the throttle actuator. This self−check insures that the ECM is functioning properly. If any malfunction is detected, the ECM will set the code and illuminate the engine light.
The ECM memory status is diagnosed by internal mirroring of the main CPU and the sub CPU to detect Random Access Memory (RAM) errors. The two CPUs also perform continuous mutual monitoring. The ECM illuminates the MIL and sets a DTC if: 1) outputs from the two CPUs are different or deviate from the standards, 2) the signals sent to the throttle actuator deviate from the standards, 3) a malfunction is found in the throttle actuator supply voltage, and 4) any other ECM malfunction is found.

More Information

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