Toyota RAV4 Service Manual: Internal control module random access memory (ram) error
Description
The ecm continuously monitors its own internal memory status, internal circuits, and output signals transmitted to the throttle actuator. This self-check ensures that the ecm is functioning properly. If any malfunction is detected, the ecm sets the appropriate dtc and illuminates the mil.
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.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Inspection procedure
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
- Check any other dtcs output (in addition to dtc p0604, p0606, p0607 or p0657)
- Connect the intelligent tester to the dlc3.
- Turn the ignition switch on.
- Turn the tester on.
- Select the following menu items: diagnosis / enhanced obd ii / dtc info / current codes.
- Read dtcs.
System voltage
Description
The battery supplies electricity to the ecm even when the ignition switch is
in the off position. This
power allows the ecm to store data such as dtc history, freeze frame data and ...
Starter relay circuit high
Description
While the engine is being cranked, the positive battery voltage is applied to
terminal sta of the ecm. If
the ecm detects the starter control (sta) signal while the vehicle is bein ...
Other materials:
Integrated Universal Remote Control
Vehicle features and
options
This chapter describes all standard, country-specific
and optional features offered with the series.
It also describes features and functions that are
not necessarily available in your vehicle, e.g., due
to the selected options or country versions. This
also applies to ...
Fail-safe chart
Fail-safe chart
This function minimizes the loss of the ect functions
when a malfunction occurs in a sensor or solenoid.
Automatic transmission fluid (atf) temperature
sensor:
when the atf temperature sensor has a
malfunction, o/d up-shift is prohibited
Counter gear speed sensor n ...
The keys
The following keys are provided with the vehicle.
Vehicles without a smart key system (type a)
Master keys
Operating the wireless remote control
function
Valet key
Key number plate
Vehicles without a smart key system (type b)
Master keys
Operating the wireless r ...
