3A3-84421-0 Tohatsu ROLLER

Use this procedure in order to troubleshoot the position sensors for the following valves:
NRS valve
Engine intake throttle valveEach position sensor is an integral part of the associated valve. If the following procedure indicates a fault with the position sensor, then the entire valve must be replaced.The following background information is related to this procedure:The troubleshooting procedures for the diagnostic codes of each position sensor are identical. The ECM supplies 5 VDC to terminal "1" of the engine intake throttle valve connector and to terminal "6" of the NRS valve connector. The sensor common from the ECM connector goes to terminal "3" of the engine intake throttle valve connector and to terminal "4" of the NRS valve connector. The sensor supply is output short circuit protected. A short circuit to the battery will not damage the circuit inside the ECM. The signal voltage from terminal "5" of the engine intake throttle valve and from terminal "2" of the NRS valve is supplied to the appropriate terminal at the P2/J2 ECM connector.
Illustration 1 g06555161
Schematic diagram for the valve position sensors
Not all connectors are shown. Refer to the appropriate Electrical Schematic.
Illustration 2 g03616849
Typical view of the pin locations on the J2 connector for the valve position sensors.
(8) Intake throttle valve position sensor 5 VDC supply
(9) NRS valve position sensor 5 VDC supply
(24) NRS valve position sensor ground
(34) Intake throttle valve return
(35) NRS valve return
(37) Intake throttle valve position sensor ground
(39) NRS valve position sensor signal
(49) Intake throttle valve PWM signal
(50) NRS valve PWM signal
(53) Engine intake throttle valve position sensor signal
Table 2
Troubleshooting Test Steps Values Results
1. Verify All Active and Recently Logged Diagnostic Codes
A. Turn the keyswitch to the ON position. Wait at least 10 seconds for activation of the diagnostic codes.
B. Verify if any of the diagnostic codes that are listed in Table 1 are active or recently logged.
Diagnostic codes
Result: None of the preceding diagnostic codes are active or recently logged.
The fault may be intermittent. Refer to Troubleshooting, "Electrical Connectors - Inspect" in order to identify intermittent faults.
Result: One or more of the preceding diagnostic codes are active or recently logged.
Proceed to Test Step 2.
2. Inspect Electrical Connectors And Wiring
A. Thoroughly inspect the terminal connections on the P2/J2 ECM connectors.
B. Thoroughly inspect the connectors for the valves.
C. Refer to Troubleshooting, "Electrical Connectors - Inspect".
D. Perform a 30 N (6.7 lb) pull test on each of the wires in the ECM connector and the valve connectors that are associated with the active diagnostic code.
E. Check the harness for abrasions and for pinch points from the valves back to the ECM.
Damaged wire or connector
Result: A damaged wire or damaged connector was found.
Repair the damaged wire or the damaged connector.
Use the electronic service tool to clear all logged diagnostic codes. Verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly connected and/or inserted and the harness is free of corrosion, of abrasion or of pinch points.
Proceed to Test Step 3.
3. Measure the Sensor Supply Voltage at the Valve Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the suspect valve from the engine harness.
C. Turn the keyswitch to the ON position.
D. Measure the voltage at the harness connector for the valve from the 5 VDC supply terminal of the position sensor to the sensor ground terminal.
4.9 v to 5.1 V
Result: The measured voltage is not within the expected range.
The fault is in the wiring between the suspect valve and the ECM P2 connector.
Check all wiring between the suspect valve and the ECM. Refer to the appropriate Electrical Schematic.
Replace the suspect wiring.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: The measured voltage is within the expected range.
Proceed to Test Step 4.
4. Verify the Type of Active Diagnostic Code
A. Turn the keyswitch to the ON position. Wait at least 10 seconds for activation of the diagnostic codes.
B. Use the electronic service tool to check for active diagnostic codes. Record all active diagnostic codes.
Diagnostic codes
Result: An XX-4 diagnostic code is active at this time.
Proceed to Test Step 5.
Result: An XX-3 diagnostic code is active at this time.
Proceed to Test Step 7.
5. Create an Open Circuit at the Valve Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the valve with the XX-4 diagnostic code.
C. Turn the keyswitch to the ON position. Wait for at least 10 seconds for activation of the diagnostic codes.
D. Use the electronic service tool to check the "Active Diagnostic Code" screen. Check for an XX-3 diagnostic code.
Note: Diagnostic codes for all of the engine sensors will be active with the P2 connector disconnected. Ignore all other codes and only look for codes that relate to the suspect valve.
E. Turn the keyswitch to the OFF position.
Diagnostic codes
Result: An XX-3 diagnostic code is active with the valve disconnected.
Reconnect the connector for the valve.
If the XX-4 diagnostic code returns, there is a short in the valve.
Install a replacement valve. Refer to Disassembly and Assembly for the correct procedure.
If the NRS valve is replaced, use the electronic service tool to perform the "EGR Valve Learn Reset".
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: There is still an XX-4 diagnostic code active with the valve disconnected.
Proceed to Test Step 6.
6. Create an Open Circuit at the ECM Connector
A. Turn the keyswitch to the OFF position.