Subaru Legacy BN/BS (2015-2019) Service Manual: Dtc p0890 tcm power relay sense circuit low

Subaru Legacy BN/BS (2015-2019) Service Manual / Continuously variable transmission (diagnostics) / Diagnostic procedure with diagnostic trouble code (dtc) / Dtc p0890 tcm power relay sense circuit low

DTC DETECTING CONDITION:

Immediately at fault recognition

TROUBLE SYMPTOM:

Improper gear shifting

WIRING DIAGRAM:

Power supply circuit Power Supply Circuit > WIRING DIAGRAM

Engine electrical system Engine Electrical System > WIRING DIAGRAM

STEP	CHECK	YES	NO
1.CHECK ECM CONNECTOR. Check the connecting condition of ECM connector.	Is the ECM connector correctly connected-	Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0890 TCM POWER RELAY SENSE CIRCUIT LOW	Connect the ECM connector correctly.
2.CHECK HARNESS BETWEEN M/B FUSE AND MAIN RELAY CONNECTOR. 1) Turn the ignition switch to OFF. 2) Measure the voltage between M/B fuse and engine ground. Connector & terminal (M/B fuse) No. 26 (+) — Engine ground (−): (B134) No. 14 (+) — Engine ground (−):	Is the voltage 10 V or more-	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	Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0890 TCM POWER RELAY SENSE CIRCUIT LOW
3.CHECK HARNESS BETWEEN ECM AND MAIN RELAY CONNECTOR. 1) Turn the ignition switch to OFF. 2) Remove the main relay. 3) Disconnect the connector from ECM. 4) Measure the resistance between the ECM connector and engine ground. Connector & terminal (B134) No. 60 — Engine ground:	Is the resistance 1 M- or more-	Repair the poor contact of ECM connector.	Repair the short circuit to ground in harness between ECM connector and main relay connector.

1. OUTLINE OF DIAGNOSIS

• Detect the malfunction of transmission fluid pressure solenoid drive power supply relay circuit.

• Judge as NG if the transmission fluid pressure solenoid drive power supply voltage is lower than the predetermined value.

2. EXECUTION CONDITION

Secondary Parameters	Execution condition
12 V battery system voltage	≥ 9 V
Ignition state	Run or Crank

3. DIAGNOSTIC METHOD

If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.

Judgment Value

Malfunction Criteria	Threshold Value
Measured TCM input voltage which is supplied from 12 V battery system through the TCM Power Relay	< 2 V

Time Needed for Diagnosis: 0.5 seconds

Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

Dtc p0951 auto shift manual control circuit range/performance

DTC DETECTING CONDITION:Immediately at fault recognitionTROUBLE SYMPTOM:Manual mode can not be set.WIRING DIAGRAM:• ENGINE TYPE FBNOTE:For the coupling connector, refer to “WIRING SYSTEM&r ...

Dtc p0843 transmission fluid pressure sensor/switch "a" circuit high

DTC DETECTING CONDITION:Immediately at fault recognitionTROUBLE SYMPTOM:Shift characteristics malfunction1. ENGINE TYPE FBWIRING DIAGRAM:CVT control system CVT Control System > WIRING DIAGRAMSTEPCHEC ...

Other materials:

Inspection
1. Measure the resistance between connector terminals.Preparation tool:Circuit testerTerminal No.Inspection conditionsStandard1 — 3Switch OFF1 M- or moreSwitch ONLess than 1 -2 — 3Switch doorLess than 1 -2. Apply battery voltage between the connector terminals to check the lighting condition of ...