
RENR5622 131
Troubleshooting Section
Results:
•
OK – A 06 diagnostic code is active when the
jumper wire is installed. A 05 diagnostic code
is active when
the jumper wire is removed. The
engine harness and the ECM are OK.
Repair: Tempo
rarily connect a new prelube relay
to the harness, but do not install the new prelube
relay. Verify that there are no active diagnostic
codes for the
prelube relay. If there are no active
diagnostic codes for the prelube relay, permanently
install the new prelube relay. Clear any logged
diagnostic c
odes.
STOP.
•
Not OK – The 05 diagnostic code remains active
with the jumper in place. The open circuit is
between the
ECM and the connector for the
prelube relay. Proceed to Test Step 5.
Test Step 5.
Test t he Operation of the
ECM
A. Turn the keyswitch to the OFF position.
B. Fabricate jumper wires that can be used to replace
the wire(s) in the ECM connector for the prelube
relay. Cri
mp a connector socket to one end of the
jumper wires.
C. Disconnec
t the appropriate ECM connector(s) for
the prelube relay.
D. Remove th
e wire(s) for the prelube relay from the
ECM connector.
E. Install t
he jumper wire(s) into the terminal
location(s) for the prelube relay at the ECM
connector.
F. Connect the ECM connectors.
G. Check the
operation of the ECM by creating
an open at the ECM:
a. Hold the l
oose end of the jumper wire away
from any components in order to create an
open circuit condition.
b. Turn the keyswitch to the ON position.
c. Proceed
to the “Diagnostic Overrides” screen
on Cat ET.
d. Activat
e the prelube system.
e. Monitor the “Active Diagnostic Code” screen
on Cat ET
.
Check the prelube relay for an active 05
diagnos
tic code.
Note: Wait at least 30 seconds so that any codes
may become acti
ve.
f. Turn the keyswitch to the OFF position.
H. Check the operation of the ECM by creating a
short circuit at the ECM:
a. Short the jumpers for the return wire and the
output wire together.
b. Turn the keyswitch to the ON position.
c. Proceed to the
“Diagnostic Overrides” screen
on Cat ET.
d. Activate the p
relube system.
e. Monitor the “Active Diagnostic Code” screen
on Cat ET.
Check the prelube relay for an active 06
diagnostic c
ode.
Note: Wait at least 30 seconds so that any codes
may become ac
tive.
I. Turn the keyswitch to the OFF position. Reconnect
all wires to t
he original configuration.
Expected Result:
A 05 diagnostic code is active when the wires from
the prelube relay are open at the ECM connector.
A 06 diagnos
tic code is active if the wires from the
prelube relay are shorted at the ECM connector.
Results:
•
OK – The ECM is operating properly. The problem
is in the wir
ing between the ECM and the connector
for the prelube relay.
Repair: Rep
air the connectors or wiring and/or
replace the connectors or wiring.
STOP.
•
Not OK – One of the following conditions exists:
The 05 diag
nostic code is not active when the
wire for the prelube relay is disconnected. The 06
diagnostic code is not active when the wire jumper
is instal
led.
Repair: Replace the ECM. Refer to
Troubles
hooting, “Replacing the ECM”.
Verify that the problem is resolved.
STOP.