164 KENR9126
Troubleshooting Section
1. Temporarily connect the suspect sensor .
2. If the diagnostic code remains active, replace
the sensor.
3. Verify that the repair eliminates the fault.
4. Clear all log
ged diagnostic codes.
STOP.
•
Not OK – The “Voltage Above Normal” diagnostic
code remains active with the jumper in place. The
most probab
le location for the open circuit is in the
sensor common or the sensor signal wire in the
engine harness between the ECM and the sensor.
Remove the
jumper. Proceed to Test Step 6.
Test Step 6. Check The Operation Of The
ECM By C reating An O pen And A Short
Circuit At The ECM Connector
A. Turn the keyswitch to the OFF position.
B. Disconn
ect the P2 connector.
C. Thoroughly inspect both halves of the connector
for sig
ns of corrosion or moisture. Refer to
Troubleshooting, “Electrical Connectors - Inspect”.
D. Turn th
e keyswitch to the ON position. Use the
electronic service tool in order to monitor the
“Active Diagnostic Code” screen. Wait at least 10
secon
ds for activation of the code.
An “Voltage Above Normal” diagnostic code
shoul
d be active for the suspect sensor.
Note: When P2 is disconnected, all of the “Voltage
Abov
e Normal” diagnostic codes for the pressure
sensors and temperature sensors will be active. This
is normal. Disregard the diagnostic codes for the
pres
sure sensors and the temperature sensors that
are not suspect. Monitor the diagnostic codes for the
suspect sensors only.
E. Turn the keyswitch to the OFF position.
F. Fab
ricate a jumper wire 150 mm (6 inch) long.
Crimp a terminal to both ends of the wire.
G. Mo
nitor the “Active Diagnostic Code” screen on
the electronic service tool before installing the
jumper wire and after installing the jumper wire.
H. Remove the suspect sensor signal pin from the P2
connector, eit
her pin P2:42 for the intake manifold
temperature sensor or pin P2:43 for the coolant
temperature sensor. Remove the P2:37 sensor
common connec
tor. 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 jumper
to the P2:37 common connection
for the sensors. Reassemble the P2 connector
to the ECM. Use the electronic service tool in
order to che
ck 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 temperature sensor that is not suspect should
become act
ive when the sensor common connection
is removed from the P2 connector. This code can be
disregarded.
Expected Result:
A“Voltag
e Below Normal” diagnostic code is active
when the jumper is installed. A “Voltage Above
Normal” diagnostic code is active when the jumper
is remove
d.
Results:
•
OK – Proceed to test step 7.
•
Not OK
Repair: The ECM does not operate correctly.
Perfor
m the following repair:
1. Make sure that the latest flash file for the
appli
cation is installed in the ECM. Refer to
Troubleshooting, “Flash Programming”.
2. Conta
ct the Technical Help Desk.
Note: This consultation can greatly reduce the repair
time
.
3. If the Technical Help Desk recommends the
use o
f a test ECM, install a test ECM. Refer t o
Troubleshooting, “Replacing the ECM”.
4. Use
the electronic service tool to recheck the
system for active diagnostic codes.
5. If t
he fault is resolved with the test ECM,
reconnect the suspect ECM.
6. If
the fault returns with the suspect ECM,
replace the ECM.
7. Us
e the electronic service tool in order to clear
all logged diagnostic codes and then verify that
the repair eliminates the fault.
STOP.
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