Circuit Description
Information is relative to transmission input speed to the transmission control module (TCM). The TCM uses transmission input speed information to control line pressure, the torque converter clutch (TCC) apply and release, and transmission shift patterns. This information is also used to calculate the appropriate operating gear ratios and TCC slippage.
The input speed sensor mounts onto piston B inside of the valve body.
An air gap of 1.8-2.2 mm (0.07-0.086 in) is maintained between the sensor and piston B.
The sensor consists of a permanent magnet surrounded by a coil of wire. As piston B is driven by the turbine shaft, an AC signal is induced by the input speed sensor. Higher vehicle speeds induce a higher frequency and voltage measurement at the sensor.
The sensor resistance should measure between 825-835 ohms at 20°C (68°F). The sensor resistence can measure from 1,000-8,000 HZ.
Conditions for Setting the DTC
| • | The input speed is more than 7,000 RPM. |
| • | The system voltage is too high or too low. |
| • | The TCM or the engine control module (ECM) is defective. |
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer. |
| • | Adopt Emergency/Substitute mode and constant 4th gear by hydraulic control. |
| • | After ignition OFF/ON, 3rd gear by hydraulic control, and the positions P, R, and N, are also possible. |
| • | Open lock up clutch |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn OFF when the malfunction has not occurred after 3 ignition cycles. |
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | Clear the DTCs with a scan tool. |
Diagnostic Aids
When DTC P0715 sets, the possible cause of the fault could be the input speed sensor (ISS).
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you performthe Diagnostic System Check-Automatic Transmission? | -- | Go to Step 2 | |
2 |
Is the speed within the specified range? | 0-7,000 RPM | Go to Diagnostic Aids | Go to Step 3 |
3 |
Is the resistance within the specified range? | 825-835 ohms | Go to Step 9 | Go to Step 4 |
4 |
Is the resistance within the values shown? | 0 ohms | Go to Step 6 | Go to Step 5 |
5 | Repair the malfunctioning terminals, as necessary. Is the action complete? | -- | System OK | -- |
6 |
Is the voltage within the specified range? | 11-14 V | Go to Step 7 | Go to Step 8 |
7 | Repair the short to battery power. Is the action complete? | -- | System OK | -- |
8 | Replace the input speed sensor. Is the action complete? | -- | System OK | -- |
9 |
Is the resistance within the specified values? | 0 ohms | Go to Step 11 | Go to Step 10 |
10 | Repair the malfunctioning terminals, as necessary. Is the action complete? | -- | System OK | -- |
11 |
Is the voltage within the specified range? | 11-14 V | Go to Step 12 | Go to Step 13 |
12 | Repair the malfunctioning terminals, as necessary. Is the action complete? | -- | System OK | -- |
13 | Replace the TCM. Refer to Transmission Control Module Replacement . Is the action complete? | -- | Go to Step 14 | -- |
14 |
Did the last test fail or is the current DTC displayed? | -- | Go to Step 2 | System OK |
