3FW-10088-0 Tohatsu AIR HOSE ASSEMBLY

Table 1
Diagnostic Codes Table
Code and Description Conditions which Generate this Code System Response
110-3 Engine Coolant Temperature Sensor voltage above normal The Electronic Control Module (ECM) detects a signal voltage that is more than 4.8 VDC for five seconds. The ECM assumes the last valid value for the engine coolant temperature. The monitoring of the coolant temperature is disabled. This disables the engine protection for low coolant temperature and high coolant temperature.
The fuel is shut off. The shutdown output is activated. The code is logged.
Since the engine protection is disabled, the engine is shut down.
The alarm output is activated.
110-4 Engine Coolant Temperature Sensor voltage below normal The ECM detects a signal voltage that is less than 0.2 VDC for five seconds. System OperationUse this procedure to troubleshoot any suspect problems with the engine's coolant temperature sensor. Refer to Troubleshooting, "Component Location" for graphics that show the location of the sensor on the in-line engines and on the vee engines.The sensor signal for the passive sensor is routed from the ECM to terminal 1 of the sensor connector. The sensor return for the passive sensors is routed from the ECM to terminal 2 of the sensor connector.The ECM continuously creates a pull-up voltage on the signal wire for each sensor. The ECM uses this pull-up voltage in order to detect a problem in the signal circuit. When the ECM detects voltage that is above a threshold on the signal wire, the ECM activates a high voltage -3 diagnostic code. When the ECM detects voltage that is below a threshold on the signal wire, the ECM activates a low voltage -4 diagnostic code.Note: There may be a delay of 30 seconds or more in order for Caterpillar Electronic Technician (ET) to display an active diagnostic code. When you check for a diagnostic code, be sure to wait at least 30 seconds.The following components can cause these codes:
Electrical connector or wiring
Sensor
ECMThe most likely cause of a code is a problem with an electrical connector or wiring. The least likely cause of a code is the ECM.
Illustration 1 g01431487
Schematic for the passive analog sensor
Illustration 2 g01420865
Terminal locations at the P1 ECM connector for the passive analog sensors
(P1-3) Analog return
(P1-27) Engine coolant temperature
Illustration 3 g01155187
Terminal locations at the connector for the passive analog sensor
(Terminal 1) Sensor signal
(Terminal 2) Analog sensor return
Illustration 4 g01431495
P5 terminals on bottom of terminal box for an in-line engine
(P5-50) Engine coolant temperature
(P5-49) Analog return
Illustration 5 g01431502
P5 terminals on bottom of terminal box for a vee engine
(P5-41) Analog return
(P5-42) Engine coolant temperature
Illustration 6 g01431198
Terminal Box
(1) ECM connector J2/P2
(2) ECM connector J1/P1
(3) 16 amp circuit breaker
(4) Connectors J3/P3 for the customer's connector
(5) Connectors J4/P4 for the optional control panel (if equipped) or for a customer's connector
(6) J5/P5 connectors for the harness from the sensors
(7) J6/P6 connectors for the harness from the sensors Test Step 1. Check for "Active" or "Logged" Diagnostic Codes
Connect Cat ET to the service tool connector.
Switch the 16 amp circuit breaker for the ECM ON. Turn the engine control switch to the STOP position.
Monitor the diagnostic codes on Cat ET. Check and record any diagnostic codes. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Determine if a diagnostic code has occurred several times. Note: A diagnostic code that is logged several times is an indication of an intermittent problem. Most intermittent problems are the result of a poor connection between a socket and a pin in a connector or of a poor connection between a wire and a terminal.
Determine if the problem is active and related to one of the following failure modes for the analog passive sensor:
-3
-4Expected Result:A diagnostic code is not active.Results:
OK - A diagnostic code is not active.Repair: There may be an intermittent electrical problem in the harness or in a connector. If an intermittent electrical problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect" for information that is related to troubleshooting these problems.STOP
Active -3 - An active -3 diagnostic code is present. The ECM detects an open in the circuit for the sensor. Proceed to Test Step 2.
Active -4 - An active -4 diagnostic code is present. Proceed to Test Step 4.Test Step 2. Check for Battery Voltage on the Signal Wire
Measure the voltage on the harness side of the sensor connector between pin 1 and engine ground for the coolant temperature sensor. Expected Result:The signal voltage is less than battery voltage.Results:
OK - The signal voltage is less than battery voltage. The circuit for the signal is not shorted to the +Battery. Proceed to Test Step 3.
Not OK - The signal voltage is equal to battery voltage.Repair: There is a short circuit to the +Battery in the harness. Repair the wiring harness or replace the wiring harness. Verify that the repair has resolved the original problem.STOPTest Step 3. Create a Short Circuit at the Connector for the Coolant Temperature Sensor
Disconnect the harness connector for the coolant temperature sensor.
Fabricate a jumper wire that is long enough to create a test circuit across the harness side of the sensor connector. Crimp connector pins to each end of the jumper wire.
Install the jumper wire between terminal 1 (sensor signal) and terminal 2 (sensor return) at the sensor connector.
Access the "Active Diagnostic Code" screen on Cat ET. Check for an active -4 diagnostic code for the coolant temperature se