Perkins M190C - Transmission Oil Temperature - Test

KENR9126 209
Troubleshooting Section
i04012489
Transmission Oil Temperature
-Test
System Opera
tion Description:
Use this procedure to troubleshoot any suspect
problems wi
ththemarinetransmissionoil
temperature sensor.
This proced
ure covers the following diagnostic codes:
•
177-03 Transmission Oil Temperature open/short
to +batt
•
177-04 Transmission Oil Temperature short to
ground
Pull-up Voltage
The ECM continuously outputs a pull-up voltage on
the circuit for the sensor signal wire. The ECM uses
this pul
l-up voltage in order to detect a problem in the
signal circuit. When the ECM detects the presence
of a voltage that is above a threshold on the signal
circuit
, the ECM will generate a 03 diagnostic code
for the sensor.
If the s
ensor is disconnected at the sensor connector,
the presence of pull-up voltage at the sensor
connector indicates that the wires from the sensor
connec
tor to the ECM are OK. If the sensor is
disconnected at the sensor connector, the absence
of pull-up voltage at the sensor connector indicates
aprob
lem in the signal wire. If the sensor is
disconnected at the sensor connector and the voltage
at the sensor connector is different from pull-up
volta
ge, the signal wire may be shorted to another
wire in the harness.
g02191975
Illustration 90
Schematic for the marine transmission oil temperature sensor
Test Step 1. Inspect the Electrical
Connectors and the Wiring
A. Remove the electrical power from the ECM.
B. Thoroughly inspect connectors on the ECM.
Inspect the connectors for the sensor. Refer to
the diagnostic functional test Troubleshooting,
“Electrical Connectors - Inspect”.