Inspection Procedure 18: 1st and 2nd Rail Switch System <M/T>

OPERATION

The 1st and 2nd rail switches detect that a transmission is shifted into the 1st speed gear position.
An engine-ECU controls an engine speed to be 3, 000 r/min or less so that an excessive load cannot be applied to a drive train system due to a sudden start in the first gear position.

PROBABLE CAUSES

Failed 1st&2nd rail switch
Damaged harness (Open circuit between 1st&2nd rail switch and engine-ECU, and open circuit between 1st&2nd rail switch and J/B)
Damaged connector (Engine-ECU connector, 1st&2nd rail switch connector)
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

Refer to Data List Reference Table .

Item 72: First shift switch

Q. Is the check result normal?

	Go to Step 7 .

	Go to Step 2 .

STEP 2. Check 1st&2nd rail switch itself

Check 1st&2nd rail switch itself (Refer to GROUP 22B - Transmission - Transmission Inspection ).

Q. Is the check result normal?

	Go to Step 3 .

	Replace the 1st&2nd rail switch.

STEP 3. Connector check: B-06 1st&2nd rail switch connector

Q. Is the check result normal?

Go to Step 4 .

Repair or replace.

STEP 4. Perform voltage measurement at B-06 1st&2nd rail switch connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal No. 1 and earth.

OK: System voltage

Q. Is the check result normal?

Go to Step 5 .

Check intermediate connector C-30, and repair if necessary. If intermediate connector is normal, check and repair harness between B-06 (terminal No. 1) 1st&2nd rail switch connector and C-208 (terminal No. 2) J/B connector.

STEP 5. Connector check: C-103 engine-ECU connector

Q. Is the check result normal?

Go to Step 6 .

Repair or replace.

STEP 6. Perform voltage measurement at C-103 engine-ECU connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal No. 104 and earth.

OK:
System voltage (Shift lever position: 1st)
0 V (Shift lever position: Neutral)

Q. Is the check result normal?

Go to Step 7 .

Check intermediate connector A-115 and C-29, and repair if necessary. If intermediate connectors are normal, check and repair harness between C-103 (terminal No. 104) engine-ECU connector and B-06 (terminal No. 2) 1st&2nd rail switch connector.

STEP 7. Check the trouble symptoms.

Q. Does trouble symptom persist?

	Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).