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.
Terminals of ecm
Check ecm
Measure the voltage of the ecm connector.
Hint:
Each ecm terminal's standard voltage is shown in
the table below.
In the table, first follow the information under
"condition". Look under "symbols (terminal no.)"
For the terminals to be inspected. ...
Driver side satellite sensor bus initialization incomplete
Description
The side airbag sensor lh consists of part including the diagnostic circuit
and the lateral deceleration
sensor.
When the center airbag sensor receives signals from the lateral deceleration
sensor, it determines
whether or not the srs should be activated.
Dtc b1643/81 is ...
Seat heater system
Parts location
System diagram
Problem symptoms table
Hint:
Use the table below to help determine the cause of the
problem symptom. The potential causes of the symptoms are
listed in order of probability in the "suspected area" column
of the table. Check each symptom by check ...