Inspection Procedure 18: First and second rail switch system <M/T>

OPERATION

The first and second rail switches detect that a transmission is shifted into the first 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 first and second rail switch
Damaged harness (Open circuit between first and second rail switch and engine-ECU, and open circuit between first and second rail switch and J/B)
Damaged connector (Engine-ECU connector, first and second 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 first and second rail switch itself

Check first and second rail switch itself (Refer to GROUP 22B - Transmission - Transmission Inspection ).

Q. Is the check result normal?

	Go to Step 3.

	Replace the first and second rail switch.

STEP 3. Connector check: C-19 first and second rail switch connector

Q. Is the check result normal?

	Go to Step 4.

	Repair or replace.

STEP 4. Perform voltage measurement at C-19 first and second rail switch connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal No. 2 and earth.

OK: System voltage

Q. Is the check result normal?

	Go to Step 5.

	Check intermediate connectors D-225, D-229, and repair if necessary. If intermediate connectors are normal, check and repair harness between C-19 (terminal No. 2) first and second rail switch connector and D-401 (terminal No. 12) J/B connector.

STEP 5. Connector check: D-215 engine-ECU connector

Q. Is the check result normal?

	Go to Step 6.

	Repair or replace.

STEP 6. Perform voltage measurement at D-215 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: First position)
0 V (Shift lever position: Neutral)

Q. Is the check result normal?

	Go to Step 7.

	Check intermediate connector D-225, and repair if necessary. If intermediate connector is normal, check and repair harness between D-215 (terminal No. 104) engine-ECU connector and C-19 (terminal No. 1) first and second 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 - Precautions Before Service - 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 ).