ELECTRICAL SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
ENGINE TEMPERATURE SENSORS OPEN OR SHORT CIRCUIT TEST - CONTINUED
Bypass harness wiring between ECM and sensor connector.
Disconnect J1/P1connector for ECM harness and suspect sensor connector (WP 0053 00).
Remove sensor signal wire from P1 ECM connector.
Remove signal wire (positive terminal) from sensor connector on engine harness.
Use jumper wire long enough to reach from ECM to sensor connector with correct terminals on both ends of wire.
Insert one end of jumper into ECM connector. Insert other end of jumper into sensor connector of engine harness.
Reconnect connector for ECM harness and sensor connector (WP 0063 00, WP 0064 00, and WP 0053 00).
Use MSD to monitor Active Diagnostic Code
screen for either open circuit diagnostic code for
sensor or short circuit diagnostic code for sensor.
Expected Results. Diagnostic code disappears
when jumper is installed.
If results are OK, a problem exists in wiring harness.
Perform this repair:
(a) Replace wiring harness in question
(WP 0169 00 thru WP 0175 00).
(b) Clear all diagnostic codes.
(c) Verify repair eliminates problem.
FUEL INJECTION PUMP CIRCUIT TEST
N OT E
· Use this test if pump is not serviceable or any of these diagnostic codes are active:
a. 1684-04 Fuel Injection Pump Short to Ground.
b. 174-02 Fuel Temperature Sensor Data Erratic plus 342-02 Loss of Secondary Engine Speed
· Fuel injection pump receives electrical supply from OEM cables and from relay for fuel pump through
machine interface connector.
· Loss of power to fuel injection pump can occur on either positive or negative side. Positive side is supplied
from pump power relay to fuel injection pump. Positive supply includes fuse to protect circuit. Negative side is
connected directly to battery.