Diagnostic Procedure

7B1: CHECK FUSE (NO. 4).
Remove fuse (No. 4).

CHECK: Is the fuse (No. 4) blown out?
1. YES: Replace fuse (No. 4). If replaced fuse (No. 4) has blown out easily, repair short circuit in harness between fuse (No. 4) and TCM.
2. NO: Go to step 7B2.
7B2: CHECK BACK-UP POWER SUPPLY CIRCUIT.
1. Turn ignition switch to ON.
2. Measure back-up power supply voltage between TCM connector terminal.
Connector & Terminal

(B55) No. 6 (+) - No. 19 (-):

Fig 1: Measuring Back-Up Power Supply Voltage Between TCM Connector Terminal

CHECK: Is the voltage more than 10 V?
1. YES: Go to step 7B3 .
2. NO: Repair open circuit in harness between fuse (No. 4) and TCM, and poor contact in coupling connector.
7B3: CHECK FUSE (NO. 5) .
Remove fuse (No. 5).

CHECK: Is the fuse (No. 5) blown out?
1. YES: Replace fuse (No. 5). If replaced fuse (No. 5) has blown out easily, repair short circuit in harness between fuse (No. 5) and TCM.
2. NO: Go to step 7B4.
7B4: CHECK IGNITION POWER SUPPLY CIRCUIT.
1. Turn ignition switch to ON (engine OFF).
2. Measure ignition power supply voltage between TCM connector terminal.
Connector & Terminal

(B54) No. 23 (+) - (B55) No. 19 (-):

Fig 2: Measuring Ignition Power Supply Voltage Between TCM Connector Terminal.

CHECK: Is the voltage more than 10 V?
1. YES: Go to step 7B5.
2. NO: Go to step 7B6.
7B5: CHECK IGNITION POWER SUPPLY CIRCUIT.
1. Turn ignition switch to ON (engine OFF).
2. Measure ignition power supply voltage between TCM connector terminal.
Connector & Terminal

(B54) No. 24 (+) - (B55) No. 19:

Fig 3: Measuring Ignition Power Supply Voltage Between TCM Connector Terminal

CHECK: Is the voltage more than 10 V?
1. YES: Go to step 7B6.
2. NO: Repair open circuit in harness between TCM and battery, and poor contact in coupling connector.
7B6: CHECK HARNESS CONNECTOR BETWEEN TCM AND TRANSMISSION.
1. Turn ignition switch to OFF.
2. Disconnect connector from transmission.
3. Measure resistance of harness between TCM and transmission connector.
Connector & Terminal

(B55) No. 19 - (B11) No. 16:

Fig 4: Measuring Resistance Of Harness Between TCM & Transmission Connector

CHECK: Is the resistance less than 1 ohm?
1. YES: Go to step 7B7.
2. NO: Repair open circuit in harness between TCM and transmission harness connector.
7B7: CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND TRANSMISSION GROUND.
Measure resistance of harness between transmission and transmission ground.

Connector & Terminal

(T4) No. 16 - Transmission ground:

Fig 5: Measuring Resistance Of Harness Between Transmission & Transmission Ground.

CHECK: Is the resistance less than 1 ohm?
1. YES: Go to step 7B8.
2. NO: Repair open circuit in harness between transmission and transmission ground.
7B8: CHECK HARNESS CONNECTOR BETWEEN INHIBITOR SWITCH AND TCM.
1. Turn ignition switch to OFF.
2. Disconnect connector from inhibitor switch.
3. Measure resistance of harness between inhibitor switch side connector and TCM.
Connector & Terminal

(B12) No. 5 - (B55) No. 19:

Fig 6: Measuring Resistance Of Harness Between Inhibitor Switch Side Connector & TCM

CHECK: Is the resistance less than 1 ohm?
1. YES: Go to step 7B9.
2. NO: Repair open circuit in harness between TCM and inhibitor side connector, and poor contact in coupling connector.
7B9: CHECK POOR CONTACT.
CHECK: Is there poor contact in control module power supply and ground line?
1. YES: Repair poor contact and ground terminal.
2. NO: Replace TCM, see TRANSMISSION CONTROL MODULE (TCM) .