MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI)
13A-13
CAUTION
To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "Interactive Diagnosis" from the start-up screen.
4. Select "System select."
5. Choose "MFI" from the "POWER TRAIN" tab.
6. Select "MITSUBISHI."
7. Select "Data List" or "Actuator Test."
8. Choose an appropriate item and select the "OK" button.
ON-BOARD DIAGNOSTICS
The powertrain control module (PCM) monitors the input/output signals (some signals all the time and others
under specified conditions) of the PCM. When a malfunction continues for a specified time or longer after the
irregular signal is initially monitored, the PCM judges that a malfunction has occurred. After the PCM first
detects a malfunction, a diagnostic trouble code is recorded when the engine is restarted and the same mal-
function is re-detected. However, for items marked with a "*", a diagnostic trouble code is recorded on the first
detection of the malfunction. There are 101 diagnostic items. The diagnostic results can be read out with a
scan tool. Since memorization of the diagnostic trouble codes is backed up directly by the battery, the diag-
nostic results are memorized even if the ignition key is turned off. The diagnostic trouble codes will, however,
be erased when the battery terminal or the PCM connector is disconnected. In addition, the diagnostic trouble
code can also be erased by turning the ignition switch to "ON" position and sending the diagnostic trouble
code erase signal from scan tool to the PCM.
NOTE: If the sensor connector is disconnected with the ignition switch turned on, the diagnostic trouble code
is memorized. In this case, send the diagnostic trouble code erase signal to the PCM in order to erase the
diagnostic memory. The 101 diagnostic items are all indicated sequentially from the smallest code number.
The PCM records the engine operating condition when the diagnostic trouble code is set. This data is called
"Freeze-frame" date. This data can be read by using the scan tool, and can then be used in simulation tests
for troubleshooting. Data items are as follows:
NOTE: If the PCM detects multiple malfunctions, the PCM stores the data for only the first item that was
detected.
However, if the PCM detects a misfire or a fuel system malfunction, PCM tores the data by giving priority to
the misfire or fuel system malfunction, regardless of the order in which the malfunction was detected.
NOTE: As for Diagnostic trouble code P1603, "freeze frame" data is not memorized.
AK303629AB
MB991911
MB991827
MB991824
16-PIN