MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <2.4L>
13A-13
INSPECTION USING SCAN TOOL MB991958,
DATA LIST AND ACTUATOR TESTING
.
Required Special Tools:
• MB991958: Scan Tool (MUT-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: USB Cable
• MB991911: Main Harness B
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 engine control module (ECM) <M/T> or powertrain control module (PCM) <A/T> monitors the input/out-
put signals (some signals all the time and others under specified conditions) of the ECM <M/T> or PCM
<A/T>. When a malfunction continues for a specified time or longer after the irregular signal is initially moni-
tored, the ECM <M/T> or PCM <A/T> judges that a malfunction has occurred. After the ECM <M/T> or PCM
<A/T> first detects a malfunction, a diagnostic trouble code is recorded when the engine is restarted and the
same malfunction is re-detected. However, for items marked with a "*," a diagnostic trouble code is recorded
on the first detection of the malfunction. There are 86 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
diagnostic results are memorized even if the ignition key is turned off. The diagnostic trouble codes will, how-
ever, be erased when the battery terminal or the ECM <M/T> or PCM <A/T> 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 ECM <M/T> or PCM <A/T>.
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 ECM <M/T> or PCM <A/T> in
order to erase the diagnostic memory. The 86 diagnostic items are all indicated sequentially from the smallest
code number. The ECM <M/T> or PCM <A/T> 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 ECM <M/T> or PCM <A/T> detects multiple malfunctions, the ECM <M/T> or PCM <A/T> stores
the data for only the first item that was detected.
AK300810
AB
MB991911
16-PIN
MB991827
MB991824