0172899 JOHNSON TRIM SWITCH ASSY.

Table 1
Example    
Reading     °C     °F    
Coolant Temperature     15 °C     59 °F    
Inlet Manifold Air Temperature     10 °C     50 °F    
Sum (1)     25 °C     109 °F    
( 1 ) The sum cannot be directly converted. The direct conversion of 25 °C is 77 °F.
Illustration 1 g00964120
Schematic
Illustration 2 g01116699
P2 ECM connector (P2-9) Air inlet heater - (P2-12) Air inlet heater +Test Step 1. Inspect Electrical Connectors and Wiring
Thoroughly inspect the J501/P501 air inlet heater relay connector and the J2/P2 ECM connector. Inspect the terminal connections on the air inlet heater relay and the air inlet heater. Refer to Troubleshooting, "Electrical Connectors-Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the air inlet heater.
Check the ECM connector (allen head screw) for the proper torque of 6 1 N m (55 9 lb in).
Check the harness and wiring for abrasion and for pinch points from the air inlet heater back to the ECM and from the air inlet heater back to the battery.Expected Result:All connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check for Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector.
Check for active diagnostic codes on Cat ET.Expected Result:A 617-05 or 617-06 diagnostic code is active for the air inlet heater relay.Results:
617-05 (Open) is Active - The ECM detects an open circuit (low current) between the relay and the ECM. Proceed to Test Step 3.
617-06 (Short) is Active - The ECM detects a short circuit (high current) between the relay and the ECM. Proceed to Test Step 4.
No Active Diagnostic Codes - There are no active diagnostic codes for the air inlet heater. Proceed to Test Step 5.Test Step 3. Check for an Open Circuit to the Relay
Disconnect the signal wires (small terminals) from the air inlet heater relay.
Install a test lamp across the wires for the relay.
Start the "Air Inlet Heater Override" on Cat ET and observe the test lamp.Note: Do not leave the "Air Inlet Heater Override" ON. Avoid unnecessary cycling of the air inlet heater in order to prevent the battery from discharging. The "Air Inlet Heater Override" has a one minute timer that disables the test when the time expires.
Stop the "Air Inlet Heater Override" and turn the keyswitch to the OFF position.Expected Result:The test lamp turned on while the override was active.Results:
OK - The open circuit is in the relay.Repair: Replace the relay and clear the diagnostic code.Verify that the repair eliminates the problem.STOP
Not OK - The open circuit is in one of the wires for the relay between the relay and the ECM.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 4. Check for a Short Circuit to the Relay
Disconnect the signal wires (small terminals) from the air inlet heater relay.
Turn the keyswitch to the ON position and check for active diagnostic codes on Cat ET.
Turn the keyswitch to the OFF position.Expected Result:The short circuit diagnostic code (617-06) changed to an open circuit diagnostic code (617-05) when the signal wires to the relay were disconnected.Results:
OK - The short circuit is in the relay.Repair: Replace the relay and clear the diagnostic codes.Verify that the repair eliminates the problem.STOP
Not OK - The short circuit is in one of the wires for the relay between the relay and the ECM.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 5. Check for Battery Voltage to the Relay
Connect a test lamp between the +Battery side of the air inlet heater relay and engine ground.Expected Result:The test lamp turns ON.Results:
OK - Battery voltage is reaching the relay. Proceed to Test Step 6.
Not OK - Battery voltage is not reaching the relay.Repair: Ensure that the circuit breaker is not tripped. Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 6. Check for Voltage Output at the Relay
Connect a test lamp between the output terminal of the air inlet heater relay and engine ground.
Observe the test lamp. The test lamp should be off, since the relay is not energized. If the test lamp is on, ensure that the test lamp is connected to the output side of the terminal.
Turn the keyswitch to the ON position.
Run the "Air Inlet Heater Override" on Cat ET and observe the test lamp.Note: Do not leave the "Air Inlet Heater Override" On. Avoid unnecessary cyc