37721-94600 Suzuki Switch, neutral

Illustration 1 g01150024
Coolant level sensor
(1) Sensor
(2) Sensor probe (brass dowel)
(3) Plastic coverCoolant level sensor (1) contains no moving parts. The sensor provides the same function as a switch. The state of the switch depends on the capacitance value that is detected at the probe of the sensor. The sensor contains a probe (2) that is covered with plastic (3).When the sensors probe is immersed in coolant, the sensor senses a particular capacitance. The sensors electronics react by sinking the signal to the digital return (ground).When the probe is not immersed in coolant, approximately +5 VDC is sourced to the signal wire. When this condition is detected by the Electronic Control Module (ECM), an event code is activated.Prior to troubleshooting any problems with the coolant level sensor, use Cat Electronic Technician (ET) to check the installation status for the sensor. The coolant level sensors configuration parameter must be set to "Installed" in order for the ECM to monitor the signal from the sensor.The activation of an event code and/or a warning lamp is probably caused by a low coolant level. The next likely cause is a problem with the wiring harness, a connector, or the sensor. The least likely cause is a problem with the ECM.
Pressurized System: Hot coolant can cause serious burns. To open the cooling system filler cap, stop the engine and wait until the cooling system components are cool. Loosen the cooling system pressure cap slowly in order to relieve the pressure.
Table 1
Troubleshooting Test Steps Values Results
1. Check the Coolant Level
A. Remove electrical power from the ECM.
Note: Allow the engine to cool prior to removal of the cooling system pressure cap.
B. Check the coolant level. Refer to the Operation and Maintenance Manual for the proper procedure to check the coolant level.
Coolant Level
Result: The coolant is at the proper level.
Proceed to Test Step 2.
Result: The coolant level is low.
1. Add coolant according to the procedure in the Operation and Maintenance Manual.
2. There may be a leak in the cooling system.
3. Identify the source of the coolant leak.
4. Repair the leak.
2. Verify that the Parameter for the appropriate “Coolant Level Sensor” is Programmed Correctly
A. Remove electrical power from the ECM.
B. Connect the Cat ET to the service tool connector.
C. Restore electrical power to the ECM.
D. Establish communication with the ECM.
E. Verify that the parameter for the suspect “Coolant Level Sensor” is programmed to “Installed”.
Coolant Level Sensor
Result: The "Coolant Level Sensor" parameter is programmed correctly.
Proceed to Test Step 3.
Result: The "Coolant Level Sensor" parameter is not programmed correctly.
Program the “Coolant Level Sensor” parameter to "Installed".
Verify that the repair eliminates the problem.
Table 2
Troubleshooting Test Steps Values Results
3. Inspect the Electrical Connectors and the Wiring
A. Remove electrical power from the ECM.
B. Thoroughly inspect the connectors for sensor (4). Also, thoroughly inspect ECM connectors (5). Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10lb)45 N (10 lb) pull test on each of the wires that are associated with the circuit for the coolant level sensor.
D. Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Electrical Connectors
Result: The harnesses and the wiring appear to be OK.
Proceed to Test Step 4.
Result: There is a problem with the connectors and/or the wiring.
Repair the wiring and connectors or replace the wiring or the connectors. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.
4. Check the Supply Voltage at the Sensor Connector
A. Disconnect the suspect coolant level sensor at the sensor connector.
B. Restore electrical power to the ECM.
C. Measure the voltage between terminals A (digital sensor supply) and B (digital return) at the harness connector for the coolant level sensor.
D. Remove electrical power from the ECM.
8.0 0.4 VDC
Result: The voltage measurement is 8.0 0.4 VDC. The supply voltage is reaching the sensor.
Proceed to Test Step 5
Result: The digital sensor supply voltage is not reaching the sensor. There is a problem in the circuit for the digital sensor supply. Refer to Troubleshooting, "Sensor Supply - Test".
STOP
5. Disconnect the Suspect Coolant Level Sensor and Monitor the Status for the Sensor
A. Disconnect the harness connector for the suspect coolant level sensor.
B. Restore electrical power to the ECM.
C. Monitor the status of the appropriate “Coolant Level” on Cat ET.
Note: Wait