MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.0L>
13B-316
.
CIRCUIT OPERATION
•
The crankshaft position sensor power is supplied
from the MFI relay (terminal 4).
•
Terminal 1 of the crankshaft position sensor is
grounded with ECM (terminal 34) <M/T> or PCM
(terminal 16) <A/T>.
•
A 5-volt voltage is applied on the crankshaft posi-
tion sensor output terminal (terminal 2) from the
ECM (terminal 43) <M/T> or PCM (terminal 45)
<A/T>. The crankshaft position sensor generates
a pulse signal when the output terminal is opened
and grounded.
.
TECHNICAL DESCRIPTION
•
The crankshaft position sensor detects the crank
angle (position) of each cylinder, and converts
that data to pulse signals, which are then input to
the ECM <M/T> or PCM <A/T>.
•
When the engine is running, the crankshaft posi-
tion sensor outputs a pulse signal.
•
The ECM <M/T> or PCM <A/T> checks whether
pulse signal is input while the engine is cranking.
.
DTC SET CONDITIONS
Check Conditions
•
Engine is being cranked.
Judgment Criteria
•
Crankshaft position sensor output voltage has not
changed (no pulse signal is input) for 2 seconds.
Check Conditions, Judgment Criteria
•
Normal signal pattern has not been input for cyl-
inder identification from the crankshaft position
sensor signal and camshaft position sensor sig-
nal for 2 seconds.
.
TROUBLESHOOTING HINTS (The most likely
causes for this code to be set are: )
•
Crankshaft position sensor failed.
•
Open or shorted crankshaft position sensor cir-
cuit, or loose connector.
•
ECM failed. <M/T>
•
PCM failed. <A/T>
DIAGNOSIS
Required Special Tool:
•
MB991502: Scan Tool (MUT-II)
AK103517 AB
CONNECTOR: B-20 <WITH VARIABLE
INDUCTION SYSTEM>
AK000225
C-52
C-55
C-51
C-58
CONNECTORS:C-51,C-58<M/T>
C-52,C-55<A/T>
ECM<M/T>
PCM<A/T>
AH
AK101363AB
MFI RELAY
CONNECTOR: A-18X