DTC P0890: TCM Power Relay Sense Circuit Low: Notes
DTC detecting condition:
Immediately at fault recognition
Trouble symptom:
Improper gear shifting
- Use CHECK BOARD when measuring the ECM terminal voltage and resistance.
- After servicing or replacing faulty parts, perform the last step of the basic diagnostic procedure. Ref. to TRANSMISSION (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .
Wiring diagram:
DC power supply circuit Ref. to WIRING SYSTEM>POWER SUPPLY CIRCUIT>WIRING DIAGRAM .
Engine electrical system Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .
- CHECK ECM CONNECTOR.
Check the connecting condition of ECM connector.
Is the ECM connector correctly connected?
Yes: Go to 2.
No: Connect the ECM connector correctly.
- CHECK HARNESS BETWEEN M/B FUSE AND MAIN RELAY CONNECTOR.
- Turn the ignition switch to OFF.
- Measure the voltage between M/B fuse and engine ground.
Connector and terminal.
(M/B fuse) No. 26 (+) - Engine ground (-):
Is the voltage 10 V or more?
Yes: Repair the harness and connector.
NOTE: In this case, repair the following item:- Short circuit to power supply of harness between M/B fuse and main relay connector
- Defective main relay
No: Go to 3.
- CHECK HARNESS BETWEEN ECM AND MAIN RELAY CONNECTOR.
- Turn the ignition switch to OFF.
- Remove the main relay.
- Disconnect the ECM connector.
- Measure the resistance between the ECM connector and engine ground.
Connector and terminal.
(B134) No. 49 - Engine ground:
Is the resistance 1 MΩ or more?
Yes: Repair the poor contact of ECM connector.
No: Repair the short circuit to ground in harness between ECM connector and main relay connector.