
RENR9348-01 161
Troubleshooting Section
D. Fabricate a jumper wire that will be long enough
to short circui
t two terminal locations at the P300
connector. Crimp connector pins to both ends of
the jumper wire.
g01203187
Illustration 91
P4 terminals that are associated with the injector s olenoids
(harness side of c onnector)
(P4-1) Injector 12 return
(P4-2) Injector 10 return
(P4-3) Injector 8 r eturn
(P4-4) Injector 6 r eturn
(P4-5) Injector 4 r eturn
(P4-6) Injector 2 r eturn
(P4-7) Injectors 10 & 1 2 s upply
(P4-8) Injectors 6 & 8 supply
(P4-9) Injectors 2 & 4 supply
g01161304
Illustration 92
P3 terminals that are associated with the injector s olenoids
(harness side of c onnector)
(P3-1) Injector 1 r eturn
(P3-2) Injector 3 r eturn
(P3-3) Injector 5 r eturn
(P3-4) Injector 7 r eturn
(P3-5) Injector 9 r eturn
(P3-6) Injector 11 return
(P3-7) Injectors 1 & 3 supply
(P3-8) Injectors 5 & 7 supply
(P3-9) Injectors 9 & 11 supply
E. Insert one end of the jumper wire into the P300
connector socket for the suspect injector’s supply
wire. Insert the other end of the jumper wire
into the P300 connector socket for the suspect
injector ’s return wire. This will replace the injector
solenoid with a short circuit.
F. Perform the “Injector Solenoid Test” at least two
times.
G. Repeat this test for each suspect circuit. Stop
the “Injector
Solenoid Test” before handling the
jumper wire.
Restore the wi
ring to the original configuration.
Expected Result:
Cat ET displays “Short” for each circuits that was
jumpered.
Results:
•
OK – Cat ET disp
lays “Short” for each circuit that
was jumpered. The harness between the ECM and
the P300 connector does not have an open circuit.
Proceed to Te
st Step 7.
•
Not OK – Cat ET displays “Open” for the cylinder
with the jump
er wire. There is a problem in the
wiring between the ECM and the P300 connector.
There may be a problem with the ECM. Proceed
to Test Step
8.
Test Step 6. Check the Harness between
theECMandtheValveCoverBasefora
Short Circ
uit
Electrical shock hazard. The electronic unit injec-
tor system uses 90-120 volts.
A. Remove the electrical power from the ECM.
B. Disconnect the appropriate P300 connector.
C. Restore the electrical power to the ECM.
D. Perform the “Injector Solenoid Test” at least two
times.
Expected Result:
All of the cylinders in the appropriate bank indicate
“Open” on Cat ET.
Results:
•
OK – All cylinders indicate “Open” on Cat ET. The
ECM and the engine harness are OK. Proceed to
Test Step 7.
•
Not OK – One or more cylinders indicate “Short”
on Cat ET. Note the cylinders that indicate “Short”.
ProceedtoTestStep8.