Transmission Control Systems

TROUBLE CODE 23: ENGINE SPEED SIGNAL

DIAGNOSIS:
Engine speed input signal circuit is open or shorted.

TROUBLE SYMPTOM:
- No lock-up (after engine warm-up)
- AT OIL TEMP indicator remains on when vehicle speed is "0".





FLOW CHART





WIRING DIAGRAM




1. CHECK HARNESS AND CONNECTOR BETWEEN TCM AND ECM.
1) Turn ignition switch to OFF.
2) Disconnect connectors from 1CM and ECM.
3) Measure resistance of harness connector between TCM and ECM.





Connector & terminal / Specified resistance:
(B96) No. 5 - (E29) No. 64 / 1 ohms, or less

4) Measure resistance of harness connector between 1CM and body to make sure that circuit does not short.





Connector & terminal / Specified resistance:
(B96) No. 5 - Body / 1 Mohms or more

2. CHECK INPUT SIGNAL FOR TCM.
1) Connect connectors to ECM and 1CM.
2) Turn ignition switch ON (with engine OFF).
3) Measure signal voltage for 1CM.





Connector & terminal / Specified voltage:
(B96) No. 5 - Body / 10.5 V, or more

- Using Subaru select monitor:
(1) Connect connectors to ECM and 1CM.
(2) Turn ignition switch to OFF.





(3) Connect the Subaru select monitor to data link connector.
(4) Turn ignition switch to ON and Subaru select monitor switch to ON.
(5) Start and warm-up the engine.
(6) Operate at constant engine speed.
(7) Read data on Subaru select monitor.
(8) Designate mode using function key.

Function mode: F06

SPECIFIED DATA:
Same as tachometer reading (in combination meter)