Toyota RAV4 (XA40) 2013-2018 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:
Compressor circuit
Description
When the a/c switch is turned on, the magnetic clutch on signal is sent from
the air conditioning
amplifier. Then the mg clt relay turns on to operate the magnetic clutch.
Wiring diagram
Inspection procedure
Perform active test by intelligent tester (a/c mag clutch)
C ...
Light control switch circuit
Description
This circuit detects the state of the headlight dimmer switch.
Wiring diagram
Inspection procedure
Read value of intelligent tester (main body ecu)
Connect the intelligent tester to the dlc3.
Turn the ignition switch on and press the intelligent
tester main switch on ...
Removal
Table of bolt, screw and nut
Hint:
All bolts, screws and nuts relevant to installing and
removing the instrument panel are shown along with
their alphabet codes in the table below.
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconne ...
