NOTE: The 1993–95, rear-wheel drive 2.4L (California)
Pick-ups have the same engine controls as the 3.0L engines. All other 2.4L engines
are listed as 2.4L engines.
To effectively troubleshoot the Multi-port Fuel Injection (MFI) system, distinct
steps or procedures should be systematically followed. Haphazard work in this
area will not effectively lead one to the true problem in the MFI system. Adhere
to the following procedures for constantly precise troubleshooting.
- Confirm the malfunction. Cause the malfunction to reoccur and check the
details of the malfunction and the conditions (engine condition, driving conditions,
etc.) when the malfunction reoccurs.
- Read the diagnostic trouble codes out. When the diagnostic trouble code
is read out and the diagnostic trouble code is output, refer to the diagnostic
procedures and repair the indicated malfunction.
- Assume the probable cause of the malfunction and determine the appropriate
check points. Refer to the procedures by their problem symptoms and confirm
the check point and the sequence of checking for the indicated malfunction.
- Check the engine control module's input and output signals. Using the scan
tool or an oscilloscope, check the input and output signals of the engine
control module. If the input and output signals are normal, sensor input/actuator
control can be judged to be normal, so check the input and output signals
of the subsequent check point.
- Check the MFI component's harness. If an abnormal condition of the input
and output signals of the engine control unit is discovered, check, and repair
if necessary, the body harness of the MFI component. After making this repair,
again check the input and output signals of the engine control module; if
they are normal proceed to the checking of the input and output signals of
the subsequent check point.
- Check the MFI component itself. If the input and output signals of the engine
control module are abnormal even though the body harness is normal, check
the MFI component itself, and repair or replace as necessary. After making
this repair or replacement, again check the input and output signals of the
engine control module; if they are normal, proceed to the checking of the
input and output signals of the subsequent check point.
