Diagnostic Procedure

8H1: CHECK HARNESS CONNECTOR BETWEEN TCM AND ECM.
1. Turn ignition switch to OFF.
2. Measure resistance of harness between TCM and ECM connector.
Connector & Terminal

(B54) No. 21 - (B135) No. 17:

Fig 1: Measuring Resistance Of Harness Between TCM & ECM Connector

CHECK: Is the resistance less than 1 ohm?
1. YES: Go to step 8H2.
2. NO: Repair open circuit in harness between TCM and ECM connector.
8H2: CHECK HARNESS CONNECTOR BETWEEN TCM AND ECM.
Measure resistance of harness between TCM and ECM connector.

Connector & Terminal

(B54) No. 13 - (B135) No. 16:

Fig 2: Measuring Resistance Of Harness Between TCM & ECM Connector

CHECK: Is the resistance less than 1 ohm?
1. YES: Go to step 8H3.
2. NO: Repair open circuit in harness between TCM and ECM connector.
8H3: CHECK HARNESS CONNECTOR BETWEEN TCM AND ECM.
Measure resistance of harness between TCM connector and chassis ground.

Connector & Terminal

(B54) No. 21 - Chassis ground:

Fig 3: Measuring Resistance Of Harness Between TCM Connector & Chassis Ground

CHECK: Is the resistance more than 1 Mohm?
1. YES: Go to step 8H4.
2. NO: Repair short circuit in harness between TCM and ECM connector.
8H4: CHECK HARNESS CONNECTOR BETWEEN TCM AND ECM.
Measure resistance of harness between TCM connector and chassis ground.

Connector & Terminal

(B54) No. 13 - Chassis ground:

Fig 4: Measuring Resistance Of Harness Between TCM Connector & Chassis Ground

CHECK: Is the resistance more than 1 Mohm?
1. YES: Go to step 8H5.
2. NO: Repair short circuit in harness between TCM and ECM connector.
8H5: CHECK OUTPUT SIGNAL EMITTED FROM TCM.
1. Turn ignition switch to ON and start engine.
2. Measure voltage between TCM connector terminals.
Connector & Terminal

(B54) No. 13 (+) - (B55) No. 19:

(B54) No. 21 (+) - (B55) No. 19:

Fig 5: Measuring Voltage Between TCM Connector Terminals

CHECK: Is each voltage more than 4.8 V?
1. YES: Even if "AT OIL TEMP" lights up, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector or harness may be the cause. Repair harness or connector in the TCM and ECM.
2. NO: Go to step 8H6.
8H6: CHECK POOR CONTACT.
CHECK: Is there poor contact in torque control signal circuit?
1. YES: Repair poor contact.
2. NO: Go to step 8H7.
8H7: CHECK GROUND LINE BETWEEN TRANSMISSION AND BODY.
Check installing condition of ground line in transmission and body.

CHECK: Is there any dirt or rust at ground line installing point?
1. YES: Remove dirt and rust.
2. NO: Go to step 8H8.
8H8: CHECK GROUND LINE BETWEEN TRANSMISSION AND BODY.
Check installing condition of ground line in transmission and body.

Tightening torque: 13+/-3 N.m (1.3+/-0.3 kg-m, 9.4+/-2.2 ft-lb)

CHECK: Is tightening torque value within specification?
1. YES: Go to step 8H9.
2. NO: Tighten to specified torque.
8H9: CHECK GROUND LINE INSIDE TRANSMISSION.
1. Drain AT fluid and remove oil pan.
2. Check tightening torque value of ground line installing bolt.
Tightening torque: 8+/-1 N.m (0.8+/-0.1 kg-m, 5.8+/-0.7 ft-lb)

Fig 6: Checking Tightening Torque Value Of Ground Line Installing Bolt

CHECK: Is tightening torque value within specification?
1. YES: Go to step 8H10.
2. NO: Tighten to specified torque.
8H10: RECHECK OUTPUT SIGNAL EMITTED FROM TCM.
Measure voltage between TCM connector terminals.

Connector & Terminal

(B54) No. 13 (+) - (B55) No. 19 (-):

(B54) No. 21 (+) - (B55) No. 19 (-):

Fig 7: Measuring Voltage Between TCM Connector Terminals

CHECK: Is each voltage more than 4.8 V?
1. YES: Replace TCM, see TRANSMISSION CONTROL MODULE (TCM) .
2. NO: Replace ECM, see ENGINE CONTROL MODULE .