MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.0L>
13B-115
.
TECHNICAL DESCRIPTION
•
The engine coolant temperature sensor converts
the engine coolant temperature to a voltage and
output it.
•
The ECM <M/T> or PCM <A/T> checks whether
this voltage is within a specified range.
.
DTC SET CONDITIONS
Check Conditions, Judgement Criteria
•
Engine coolant temperature decreases from
higher than 40
°
C (104
°
F) to lower than 40
°
C
(104
°
F).
•
Then the engine coolant temperature has contin-
ued to be 40
°
C (104
°
F) or lower for 5 minutes.
Check Conditions, Judgement Criteria
•
About 60
−
300 seconds have passed for the
engine coolant temperature to rise to about 7
°
C
(45
°
F) after starting sequence was completed.
•
However, time is not counted when fuel is shut
off.
.
TROUBLESHOOTING HINTS (The most likely
causes for this code to be set are: )
•
Engine coolant temperature sensor failed.
•
Open or shorted engine coolant temperature sen-
sor circuit, or loose connector.
•
ECM failed. <M/T>
•
PCM failed. <A/T>
DIAGNOSIS
Required Special Tools
•
MB991502: Scan Tool (MUT-II)
STEP 1. Using scan tool MB991502, check data list item 21:
Engine Coolant Temperature Sensor.
CAUTION
To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991502 to the data reading mode for item
21, Engine Coolant Temperature Sensor.
•
The engine coolant temperature and temperature
shown with the scan tool should approximately match.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES :
It can be assumed that this malfunction is intermittent.
Refer to GROUP 00, How to Use Troubleshooting/
Inspection Service Points
NO :
Go to Step 2.
AKX01177
16 PIN
MB991502
AB