SAAB WIS ONLINE

DTC P0865 TCM COMMUNICATION CIRCUIT LOW

DTC P0865 TCM COMMUNICATION CIRCUIT LOW

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 less than 1 V?

Yes


No

• 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



CHECK HARNESS BETWEEN ECM AND TCM CONNECTOR.

Turn the ignition switch to OFF.

Disconnect the connector from ECM and TCM.

Measure the resistance of harness between ECM and chassis ground.

Connector & terminal

(B135) No. 20 — Chassis ground:

Is the resistance less than 10 Ω?

Yes


No

Repair the ground short circuit in harness between ECM and TCM connector.


CHECK OUTPUT SIGNAL FOR ECM.

Connect the connector to ECM.

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 5 V?

Yes


No

Repair the poor contact in ECM connector.


CHECK DTC FOR AUTOMATIC TRANSMISSION.

Read the DTC for automatic transmission.

Does the DTC appear for automatic transmission?

Yes

Inspect the DTC for automatic transmission.


No

Replace the TCM.