P0725

DTC P0725 Engine Speed Input Circuit:

DTC P0722 Engine Speed Input Circuit:

CIRCUIT DESCRIPTION

The Noise Suppressor Filter is connected between the ignition coil and the Transmission Control Module (TCM). The TCM receives ignition pulses to determine engine speed (rpm). By knowing engine speed and vehicle speed (through VSS), the TCM calculates the input/output ratio to monitor transmission performance.


DTC DETECTING CONDITION

With engine coolant temperature signal being inputted (engine miming) for five seconds and this occurred during two driving cycles.


ACTION TAKEN

A DTC P0725 is stored and both the "OD/OFF" and the "SERVICE ENGINE SOON" indicators are turned "ON."

DTC CHART TEST DESCRIPTION

Numbers below refer to circled numbers on the diagnostic chart.

1. Checks the Noise Suppressor Filter.

2. Checks for proper voltage values.

3. Checks for a poor connector terminal contact.

4. This step determines whether the condition is intermittent and not by a faulty TCM.

5. Checks for an open or short to ground in BRN wire between the TCM and the Noise Suppressor Filter.


DIAGNOSTIC AIDS

An intermittent condition may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Inspect the TCM harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and for poor terminal-to-wire connections.