3AC-76065-0 Tohatsu RECTIFIER

Table 1
Diagnostic Trouble Codes for Analog Throttles
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
91-3 91-3 Accelerator Pedal Position 1 : Voltage Above Normal The Electronic Control Module (ECM) detects one of the following conditions:
The ECM has been powered for 3 seconds.
Diagnostic code 168-4 is not active.
3509 (262) codes are not active.
The setting for the upper diagnostic limit has been exceeded for one second.
If equipped, the warning lamp will come on. The diagnostic code will be logged.
29-3 774-3 Accelerator Pedal Position 2: Voltage Above Normal
91-4 91-4 Accelerator Pedal Position 1 : Voltage Below Normal The ECM detects one of the following conditions:
The ECM has been powered for 3 seconds.
Diagnostic code 168-4 is not active.
3510 (2131) codes are not active.
The setting for the lower diagnostic limit has been exceeded for one second.
If equipped, the warning lamp will come on. The diagnostic code will be logged.
29-4 774-4 Accelerator Pedal Position 2: Voltage Below Normal
Follow the troubleshooting procedure in order to identify the root cause of the fault. If a fault occurs with the primary throttle with secondary throttle is installed, the secondary throttle will be used until the fault is repaired.If a fault occurs with the secondary throttle, the engine will use the primary throttle until the fault is repaired.If a functional throttle is not available, the following conditions will occur:
The engine will default to the limp home speed.
If the engine speed is higher than the limp home speed, the engine will decelerate to the limp home speed.
If the engine speed is lower than the limp home speed, the engine speed will remain at the current speed.
The engine will remain at this speed while the diagnostic code remains active.
All inputs from the faulty throttle are ignored by the ECM until the fault is repaired.
All inputs from the repaired throttle will be ignored by the ECM until the keyswitch has been cycled.The diagnostic codes above relate to an analog sensor. Use this procedure only if the analog sensor uses an output from a variable resistor.The sensor is most likely to be mounted on a throttle pedal. The sensor is attached directly to the throttle assembly. The sensor provides an output voltage to the ECM. The sensor output voltage will vary with the position of the throttle. Foot operated or hand operated throttle assemblies are available.The sensor receives +5 V power from the ECM. The sensor will produce a raw signal voltage that will alter between low idle and high idle. The voltage is changed into a throttle position within the range 0% to 100% by the ECM.The sensor senses the speed requirement from the throttle position. A second sensor may override this speed requirement from the first sensor. This override will be subject to an input from a secondary throttle or from the SAE J1939 (CAN) data link or from a PTO control.Use the electronic service tool in order to check the input status.Note: The identification letters for the terminals in the connectors may vary dependent on the manufacturer of the throttle pedal.
Illustration 1 g06382094
Schematic diagram for the analog throttle position sensors
Not all connectors are shown. Refer to the Electrical Schematic for the application.
Illustration 2 g06382098
Typical example of the P1 pin locations for the analog throttle position sensor
(33) Analog throttle position sensor (1) ground
(34) Analog throttle position sensor (2) ground
(41) Analog throttle position sensor (1) 5 V supply
(42) Analog throttle position sensor (2) 5 V supply
(54) Analog throttle position sensor (1) signal
(55) Analog throttle position sensor (2) signal
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Turn the keyswitch to the OFF position.
B. Thoroughly inspect the terminal connections on the P1/J1 ECM connector, P2/J2 ECM connector and the analog throttle position sensors.
Refer to Troubleshooting, "Electrical Connectors - Inspect".
C. Check the harness for corrosion, abrasion, and pinch points from the analog throttle position sensors to the ECM.
Note: Do not disconnect the ECM connectors at this stage. The ECM can only be disconnected and reconnected 10 times before damage to the harness connector may occur.
Loose connection or damaged wire
Result: There is a fault in a connector or the wiring.
Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all of the seals are properly in place and ensure that the connectors are correctly coupled.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points.
Proceed to Test Step 2.
2. Check for Active Diagnostic Codes
A. Turn the keyswitch to the OFF position.
B. Connect the electronic service tool to the diagnostic connector.
C. Turn the keyswitch to the ON position. Wait at least 10 seconds for activation of the diagnostic codes.
D. Verify if any of the diagnostic codes that are listed in Table 1are active.
E. Turn the keyswitch to the OFF position.
Diagnostic codes
Result: There are no active diagnostic codes for the analog throttle position sensors.
Proceed to Test Step 3.
Result: One or more of the diagnostic codes listed in Table 1is active.
Proceed to Test Step 5.
3. Check the Throttle Position with the Electronic Service Tool
A. Connect the electronic service tool to the diagnostic connector.
B. Turn the keyswitch to the ON position. Do not start the engine.
C. Observe the throttle position reading on the electronic service tool.
D. Operate the throttle over the full range of movement.
20 percent to 27 percent at low idle.
80 percent to 87 percent at high idle
Result: The ECM is not receiving the correct signal from the sensor.
Repair: Use the electronic service tool to verify that the throttle has been configured correctly before continuing with this procedure.
If the fault is still present after the throttle has been configured correctly, replace the analog throttle position sensor.
Result: The sensor is operating correctly.
Proceed to Test Step 4.
4. Check the Throttle Selection Status with the Electronic Service Tool
A. Check the status of the throttle selection switch (if equipped). Use the electronic service tool in order to check the status of the throttle selection switch.
Throttle 1 has control when status