PRE-RELEASE
DTC P0725 ENGINE SPEED INPUT CIRCUIT
| DTC P0725 ENGINE SPEED INPUT CIRCUIT |
DIAGNOSIS:
The engine speed input signal circuit is open or shorted.
TROUBLE SYMPTOM:
| • |
No lock-up (after engine warm-up).
|
|
| • |
The AT OIL TEMP warning light remains
on when vehicle speed is “0”.
|
|
WIRING DIAGRAM:
CHECK HARNESS CONNECTOR BETWEEN TCM AND ECM.
Turn the ignition switch to OFF.Disconnect the connectors from TCM and ECM.
Measure the resistance of harness between TCM and ECM connector.
Connector & terminal
(B55) No. 13 — (B134) No. 23:
Is the resistance less than 1 Ω?
| Yes |
| No |
Repair the open circuit in harness between TCM and ECM connector.
CHECK HARNESS CONNECTOR BETWEEN TCM AND ECM.
Measure the resistance of harness between TCM connector and chassis ground.Connector & terminal
(B55) No. 13 — Chassis ground:
Is the resistance more than 1 MΩ?
| Yes |
| No |
Repair the short circuit in harness between TCM and ECM connector.
CHECK INPUT SIGNAL FOR TCM USING Vehicle Diagnostic Interface.
Connect the connectors to TCM and ECM.Connect the Vehicle Diagnostic Interface to data link connector.
Start the engine and turn Vehicle Diagnostic Interface switch to ON.
Idle the engine.
Read the data of engine speed using Vehicle Diagnostic Interface.
| • |
Display
shows the engine speed signal value sent from ECM.
|
|
Is the revolution value same as tachometer reading shown on combination meter?
| Yes |
Even if the POWER indicator blinks, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector or harness may be the cause. Repair the harness or connector in TCM and ECM.
| No |
CHECK POOR CONTACT.
Is there poor contact in engine speed signal circuit?
| Yes |
Repair the poor contact.
| No |
CONFIRM DTC P0725.
Replace the ECM with a new one.Does the DTC appear again, after memory has been cleared?
| Yes |
Replace the TCM.
| No |
Replace the ECM.
