1A-250 Engine Control System
Default Matrix Table
Symptom Diagnosis Chart
* Using Symptom Diagnosis Chart 1, cross-check the
symptom (column) and item number and diagnose the
current fault according to the procedure in Symptom
Diagnosis Chart 2.
5
1.
Replace the ECM.
IMPORTANT:
If necessary (for the vehicle equipped with
idle stop function), input the number of
startups to the replacing ECM.
Is the action complete?
—
Verify repair and
go to Step 6
—
6
Check DTC543 will not be set again.
1.
Using Tech 2, clear the DTC.
2.
Perform test run and review the DTC.
Is DTC543 detected?
—
Refer to
Diagnostic Aids
and go to Step 2
Repair is
complete
Symptom
Definitions
No cranking
When the starter switch is moved to the position "ST", the starter is not
activated.
No initial combustion
The engine provides cranking but does not run.
Poor startability at ordinary temperature The engine runs after long startup process.
Poor startability at low temperature
The engine shows good startability at ordinary temperature but it takes
long time to start at low temperature.
Hunting / instable idling
The idle speed is instable or varying. In the serious case, the engine or
vehicle may vibrate, resulting in occasional stall/stop.
High idle speed
The idle speed is much higher than the specified level.
Low idle speed
The idle speed is much lower than the specified level.
Engine stall before warm-up
The engine frequently stalls before warm-up.
Engine stall after warm-up
The engine frequently stalls after warm-up.
Short power / poor response / stumble
The engine output is less than the desired level and even pressing the
accelerator pedal extensively will hardly or not increase the engine
speed.
Black smoke
Lots of black smokes are generated on the road test.
White smoke
Lots of white smokes are generated on the road test.
Large engine vibration
The engine generates unusual vibrations as high as the driver feel them
in the cab.
Unusual sound
Unusual sounds such as beep or rattling sounds are generated.
Step
Action
Value(s)
Yes
No
