144 KENR6933
Troubleshooting Section
•
Not OK – The “Voltage Above Normal” diagnostic
code remains ac
tive with the jumper in place. The
most probable location for the open circuit is in the
sensor common or the sensor signal wire in the
engine harnes
s between the ECM and the sensor.
Remove the jumper. Proceed to Test Step 6.
Test Step 6. C
heck The Operation Of The
ECM By Creati
ng An Open And A Short
Circuit At T
he ECM Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the P2 connector.
C. Thoroughly
inspect both halves of the connector
for signs of corrosion or moisture. Refer to
Troubleshooting, “Electrical Connectors - Inspect”.
D. Turn the keyswitch to the ON position. Use the
electronic service tool in order to monitor the
“Active Di
agnostic Code” screen. Wait at least 10
seconds for activation of the code.
An “Voltag
e Above Normal” diagnostic code
should be active for the suspect sensor.
Note: When
P2 is disconnected, all of the “Voltage
Above Normal” diagnostic codes for the pressure
sensors and temperature sensors will be active. This
is normal
. Disregard the diagnostic codes for the
pressure sensors and the temperature sensors that
are not suspect. Monitor the diagnostic codes for the
suspect s
ensors only.
E. Turn the keyswitch to the OFF position.
F. Fabricate a jumper wire 150 mm (6 inch) long.
Crimp a terminal to both ends of the wire.
G. Monitor the “Active Diagnostic Code” screen on
the electronic service tool before installing the
jumper w
ire and after installing the jumper wire.
H. Remove the suspect sensor signal pin from the P2
connect
or, either pin P2:42 for the intake manifold
temperature sensor or pin P2:43 for the coolant
temperature sensor. Remove the P2:37 sensor
common c
onnector. Install the jumper on the P2
connector. Install one end of the jumper at the
suspect sensor signal pin. Install the other end
of the j
umpertotheP2:37commonconnection
for the sensors. Reassemble the P2 connector
to the ECM. Use the electronic service tool in
order
to check the diagnostic codes. Wait at least
10 seconds for activation of the “Voltage Below
Normal” diagnostic code.
Note: The “Voltage Above Normal” diagnostic code
for the tempera
ture sensor that is not suspect should
become active when the sensor common connection
is removed from the P2 connector. This code can be
disregarded.
Expected Result:
A “Voltage Below Normal” diagnostic code is active
when the jumper is installed. A “Voltage Above
Normal” diag
nostic code is active when the jumper
is removed.
Results:
•
OK – Proceed to test step 7.
•
Not OK
Repair: The E
CM does not operate correctly.
1. Temporarily connect a test ECM.
Note: The test ECM should be programmed with the
correct software. All parameters should be set to the
same value o
f the suspect ECM.
2. Remove all jumpers and reconnect all
connectors
.
3. If the fault is eliminated with the test ECM,
reconnect t
he suspect ECM and verify that the
fault returns.
4. If the fault
returns replace the suspect ECM.
Refer to Troubleshooting, “Replacing the ECM”.
5. Use the ele
ctronic service tool in order to clear
all logged diagnostic codes and then verify that
the repair eliminates the fault.
STOP.
Test Step 7
. Bypass The Harness Wiring
Between Th
e ECM And The Sensor
Connector
A. Turn the ke
yswitch to the OFF position.
B. Disconnect the P2 connector on the ECM harness,
and the su
spect sensor connector.
C. Remove the sensor signal wire from the P2
connecto
r.
D. Remove the signal wire (terminal 1) from the
sensor co
nnector on the engine harness.
E. Fabricate a jumper wire that is long enough to
reach fro
m the ECM to the sensor connector with
sockets on both ends.
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