
138 RENR9348-01
Troubleshooting Section
g01223579
Illustration 6 5
Schematic for the engine s peed/timing sensors
Test Step 1. Check for Diagnostic Codes
A. Connect Cat ET to the service tool connector.
Refer to Troubleshooting, “Electronic Service
Tools ” .
B. Restore electrical power to the ECM.
C. Start the engine and run the engine until the
engine is at the normal operating temperature.
Note: If the engine will not start, monitor the engine
rpm on Cat ET while the engine is being cranked. Cat
ET may need to be powered from another battery
while the engine is being cranked.
D. Look for these codes on Cat ET:
•
190-08
•
342-08
Expected Result:
One or both of the diagnostic codes that are listed
above are logged or active.
Note: If the engine will not start and Cat ET displayed
0 rpm during cranking, select “No Engine rpm”.
Results:
•
No Engine rpm – Engine rpm is not indicated on
Cat ET. Proceed to Test Step 2.
•
190-08or342-08code –Thereisanactive
diagnostic code or a logged diagnostic code for
an engine speed/timing sensor. Proceed to Test
Step 4.
•
No codes – Neither code is active or logged.
Repair: Refer to the appropriate symptoms in
Troubleshooting, “Troubleshooting Without a
Diagnostic Code”.
STOP.
Test Step 2. Check t he Installation of th e
Sensor Assembly
A. Remove electrical power from the ECM.
g01167684
Illustration 66
Typical engine s peed/timing sensor
(1) Mounting flange
(2) Mounting surface
B. Visually inspect each sensor assembly without
removing the sensor assembly from the engine.
Ensure that flange (1) is installed squarely against
surface (2).
C. Remove the suspect sensor assembly from the
engine.