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 the 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 running) for 5 seconds and this occurred during 2 driving cycles.
Action Taken
A DTC P0725 is stored and both the OD/OFF and the Malfunction Indicator Lamp (MIL) indicator turns ON.
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.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step checks the noise suppressor filter.
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This step checks for proper voltage values.
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This step checks for a poor connector terminal contact.
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This step determines whether the condition is intermittent and not by a faulty TCM.
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This step checks for an open or short to ground in BRN wire between the TCM and the noise suppressor filter.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the On-Board Diagnostic (OBD) System Check performed? | -- | ||
2 | Does the engine start? | -- | Go to Ignition System Diagnostics in Engine Controls | |
Is the noise suppressor in good condition? | -- | |||
Is the voltage within the proper range? | 11-14 V | |||
Inspect the TCM connector terminal 4 for poor contact. Is poor terminal contact or a poor connection evident? | -- | |||
Does the DTC reset? | -- | |||
7 | Replace the noise suppressor filter. Refer to Engine Controls. Is the procedure complete? | -- | -- | |
Is the resistance within the proper range? | 2 ohms or less | |||
9 | Repair the short to ground in the BRN wire between the TCM and the noise suppression filter. Is the repair complete? | -- | -- | |
10 | Repair the open or high resistance in the BRN wire between the TCM and the noise suppression filter. Is the repair complete? | -- | -- | |
11 | Repair the terminals or the connection integrity that exhibits poor contact. Is the repair complete? | -- | -- | |
12 | The malfunction is not present at this time. Refer to Diagnostic Aids. Is the action complete? | -- | -- | |
13 | Replace the TCM. Is the procedure complete? | -- | -- | |
14 | Perform the DTC Confirmation Procedure. Does the scan tool display any DTCs? | -- | Go to the applicable DTC table | System OK |
