Transmission Control Systems

TROUBLE CODE 23
ENGINE SPEED SIGNAL

Diagnosis
Engine speed input signal circuit is open or shorted.

Trouble Symptom
No lock-up occurs (after Engine warm-up).












1. Check Harness and connector between Transmission Control Module (TCM) and Engine Control Module (ECM).
a. Turn Ignition Switch to "OFF".
b. Disconnect connector from TCM and ECM.






c. Measure resistance of harness connector between TCM and ECM.
Connector & Terminal / Specified Resistance:
(B54) No. 5 - (B84) No. 33 / 1 Ohm, or less.






d. Measure resistance of harness connector between TCM and body to make sure that circuit does not short.
Connector & Terminal / Specified Resistance:
(B54) No. 5 - Body / 1 M-Ohm, or more.

2. Check input signal for TCM.
a. Connect connectors to ECM and TCM.
b. Turn Ignition Switch "ON" (with Engine OFF).






c. Measure signal voltage for TCM.
Connector & Terminal / Specified Voltage:
(B54) No. 5 - Body / 10.5 Volts, or more.

Using Subaru Select Monitor






1. Connect connectors to ECM and TCM.
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).