P1781

DTC P1781

DTC Descriptor
This diagnostic procedure supports the following DTC:

DTC P1781 Malfunction of Engine Speed Signal

Conditions for Setting the DTC
^ The transmission control module (TCM) detects that malfunction of engine speed signal for 2 seconds.
^ No DTC U2105

Action Taken When the DTC Sets
^ The TCM will request the illumination of the malfunction indicator lamp (MIL) and store the DTC when the TCM detects a failure on the first ignition cycle.
^ No engine torque reduction control
^ No lock-up
^ No engagement pressure control
^ No 4th gear
^ No self-learning control
^ No timing solenoid control for N-D
^ The TCM judges the engine revolution is 0 RPM.

Conditions for Clearing the DTC
^ The TCM turns OFF the MIL when no further failures are detected on the next ignition cycle.
^ The scan tool can clear the DTC from the TCM history.
^ The TCM clears the DTC from the TCM history memory after 40 consecutive ignition cycles without fault.

Cause of Failure
^ The wiring harness or the connector between the engine control module (ECM) and the TCM
^ The ECM
^ The TCM

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Step 11: