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DTC P0866 TCM COMMUNICATION CIRCUIT HIGH

DTC P0866 TCM COMMUNICATION CIRCUIT HIGH

DTC DETECTING CONDITION:


• Two consecutive driving cycles with fault

• GENERAL DESCRIPTION


Important

After repair or replacement of faulty parts, conduct Clear Memory Mode and Inspection Mode .


WIRING DIAGRAM:


CHECK HARNESS BETWEEN ECM AND TCM CONNECTOR.

Turn the ignition switch to ON.

Measure the voltage between ECM and chassis ground.

Connector & terminal

(B135) No. 20 (+) — Chassis ground (−):

Is the voltage more than 10 V?

Yes

Repair the battery short circuit in harness between ECM and TCM connector. After repair, replace the ECM.


No


CHECK HARNESS BETWEEN ECM AND TCM CONNECTOR.

Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B135) No. 20 (+) — Chassis ground (−):

Is the voltage more than 4 V?

Yes


No


CHECK HARNESS BETWEEN ECM AND TCM CONNECTOR.

Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B135) No. 20 (+) — Chassis ground (−):

Is the voltage less than 1 V?

Yes

Repair the poor contact in ECM connector.


No


CHECK OUTPUT SIGNAL FROM ECM.

Measure the voltage between ECM and chassis ground.

Connector & terminal

(B135) No. 20 (+) — Chassis ground (−):

Does the voltage change between 1 and 4 V while monitoring the value with voltage meter?

Yes

• Even if malfunction indicator light lights up, the circuit has returned to a normal condition at this time.

•
Note

In this case, repair the following:

• Poor contact in ECM connector

• Poor contact in TCM connector



No

Contact Service Center.


CHECK HARNESS BETWEEN ECM AND TCM CONNECTOR.

Measure the voltage between TCM and chassis ground.

Connector & terminal

(B56) No. 20 (+) — Chassis ground (−):

Is the voltage more than 4 V?

Yes


No

Repair the open circuit in harness between ECM and TCM connector.


CHECK POOR CONTACT.

Check poor contact in TCM connector.

Is there poor contact in TCM connector?

Yes

Repair the poor contact in TCM connector.


No

Check the TCM power supply line and grounding line.