MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.0L>
13B-86
.
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
•
2 seconds or more have passed since the staring
sequence was completed.
Judgement Criteria
•
Engine coolant temperature sensor output volt-
age has continued to be 0.1 volt or lower [corre-
sponding to a coolant temperature of 140
°
C
(284
°
F) or higher] for 2 seconds.
.
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.
STEP 2. Check connector B-11 at the engine coolant
temperature sensor for damage.
Q: Is the connector in good condition?
YES :
Go to Step 3.
NO :
Repair or replace it. Refer to GROUP 00E, Harness
Connector Inspection
. Then go to Step 6.
AKX01177
16 PIN
MB991502
AB
ACX02490
CONNECTOR : B-11
ENGINE
COOLANT
TEMPERATURE
SENSOR
AC