
RENR5622 95
Troubleshooting Section
Test Step 2. Check for a “LOGGED”
Diagnostic Code
A. Connect Caterpillar Electronic Technician (ET) to
the service tool connector.
B. Turn the k eyswitch to the ON position.
C. Check the diag
nostic codes on Cat ET.
Expected Result:
Cat ET indicates that a 190-08 diagnostic code has
recently been logged.
Results:
•
OK – The 190-08
diagnostic code is logged.
Proceed to Test Step 3.
•
Not OK – The 19
0-08 is not logged.
Repair: The problem is no longer present. If the
problem is in
termittent, refer to Troubleshooting,
“Inspecting Electrical Connectors”.
STOP.
Test Step 3. Check the Su pply Voltage to
the Sensor
A. Disconnect the connector for the engine
speed/timing sensor.
B. Turn the k eyswitch to the ON position.
C. Measure the
voltage between terminal A and
terminal B at the sensor connector.
Expected R
esult:
The supply voltage is 12 ± 1.0 VDC.
Results:
•
OK – The supp
ly voltage is 12 ± 1.0 VDC. Proceed
to Test Step 4.
•
Not OK – The
supply voltage is not 12 ± 1.0 VDC.
Proceed to Test Step 6.
Test Step 4
. Ch eck the Signal Voltage at
the Senso
r
A. Turn the keyswitch to the OFF position.
B. RemovethewirefromterminalCofthesensor
connector.
C. Turn the k eyswitch to the ON position.
D. Measure the voltage between the sensor signal
wire and termi n
al B of the sensor connector. Crank
the engine and measure the voltage between the
sensor signal wire and terminal B.
E. Turn the keyswitch to the OFF position.
F. Reconnect the
signal wire.
Expected Result:
The voltage measures less than 3 VDC or more than
9VDCwhenthekeyswitchisintheONposition
and the engin
e is not cranking. While the engine is
cranking, the voltage is between 2.0 VDC and 7.0
VDC.
Note: The voltage output is determined by the
presence or the absence of a tooth on the timing gear.
Results:
•
OK – The engin
e speed/timing sensor is producing
the correct output signal. Proceed to Test Step 5.
•
Not OK – The e
ngine speed/timing sensor is not
producing the correct output signal.
Repair: Rep
lace the engine speed/timing sensor.
Calibrate the sensor. Perform the calibration
procedure Troubleshooting, “Engine Speed/Timing
Sensor - Cal
ibrate”.
STOP.
Test Step 5. Check the Signal Voltage at
the ECM
A. Turn the ke
yswitch to the OFF position.
B. Disconnect ECM connector J1/P1.
C. Remove wire 999-WH from ECM connector P1-33.
D. Reconnect
ECM connector J1/P1.
E. Turn the keyswitch to the ON position.
F. Measure the signal voltage between the signal
wire 999-WH and engine ground.
G. Crank the engine and measure the signal voltage
between the signal wire 999-WH and engine
ground.
H. Turn the keyswitch to the OFF position.
I. Replace all wires. Reconnect ECM connector
J1/P1.