MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.0L>
13B-403
•
Open fuel tank differential pressure sensor cir-
cuit, or loose connector.
•
ECM <M/T> or PCM <A/T> failed.
.
OVERVIEW OF TROUBLESHOOTING
•
The DTC P0452 can be set if either of the follow-
ing conditions occur:
1. Faulty fuel differential pressure sensor,
related circuit, or ECM <M/T> or PCM <A/T>.
•
To check a system blockage, do a performance
test which uses a mechanical vacuum gauge and
scan tool MB991502 set on the fuel tank differen-
tial pressure sensor (TANK PRS SNSR 73.)
The mechanical gauge reading is used to verify
scan tool MB991502 reading.
A comparison of the mechanical gauge to scan
tool MB991502 determines the problem in the
system.
.
DIAGNOSIS
Required Special Tools:
•
MB991502: Scan Tool (MUT-II)
•
MB991658: Test Harness Set
•
MB991709: Test Harness Set
STEP 1. Using scan tool MB991502, check data list item 73:
Fuel Tank Differential Pressure 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) Disconnect hose I from the evaporative emission canister
side, and plug the hose from which the pipes have been
disconnected.
(3) Turn the ignition switch to the "ON" position.
(4) Remove the fuel cap.
(5) Set scan tool MB991502 to the data reading mode for item
73, Fuel Tank Differential Pressure Sensor.
•
The fuel tank pressures should be
−
1.5 to 1.5kPa (
−
285
to 285 inHg.)
(6) Connect an evaporative emission system pressure pump to
the fuel filler neck, and apply pressure.
•
The scan tool reading should increase.
(7) Turn the ignition switch to the "LOCK" (OFF) position. Then
disconnect scan tool MB991502.
Q: Is the scan tool reading within the specified value?
YES :
Go to Step 22.
NO :
Go to Step 2.
AC001252
MB991502
16 PIN
AB
AC002072 AB
HOSE I
AC000186