Circuit Description
The torque converter stator temperature switch is a normally-open, temperature-sensitive switch which sends a signal to the PCM to begin action to cool the torque converter. At 164°C (327°F) the switch will close and the signal to the PCM will change to 0 volts. This switch is a single lead switch that grounds through the transmission fluid cooler pipes.
When the PCM detects the torque converter stator switch does not indicate a hot mode at a high transmission temperature, then DTC P1874 sets. DTC P1874 is a type D DTC.
Conditions for Setting the DTC
| • | No TFT DTCs P0712 or P0713. |
| • | The TFT is greater than 140°C (284°F). |
| • | Torque converter stator temperature switch circuit does not indicate a hot mode. |
| • | All conditions met for 15 seconds. |
Action Taken When the DTC Sets
| • | Torque converter stator temperature switch indicates a hot mode. |
| • | The PCM freezes shift adapts from being updated. |
| • | The PCM will NOT illuminate the Malfunction Indicator Lamp (MIL). |
Conditions for Clearing the DTC
| • | A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported. |
| • | The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM. |
Diagnostic Aids
| • | If the switch and external wiring checks okay, verify the circuit ground integrity through the transmission fluid cooler pipes. |
| • | Inspect the wiring for poor electrical connections at the PCM. Look for the following conditions: |
| - | A bent terminal |
| - | A backed out terminal |
| - | A damaged terminal |
| - | Poor terminal tension |
| - | A chafed wire |
| - | A broken wire inside the insulation |
| • | When diagnosing for a possible intermittent short or open condition, massage the wiring harness while watching test equipment for changes. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Powertrain On Board Diagnostic (OBD) System Check , Section 6 | |
2 | Perform the Automatic transmission fluid checking procedure. Refer to Transmission Fluid Check . Has the transmission fluid checking procedure been performed? | -- | Go to Transmission Fluid Check | |
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. Does the scan tool display "TCC Stator Temp." as "high" (closed switch) with the test light connected and "normal" (open switch) with the test light disconnected? | -- | |||
4 | Is "normal" (open switch) displayed at all times? | -- | Go to Diagnostic Aids | |
5 | Inspect/repair circuit 585 for an open or short to Battery Voltage. Refer to Electrical Diagnosis, Section 8. Is the repair complete? | -- | -- | |
6 | Replace the torque converter stator temperature switch. Is the replacement complete? | -- | -- | |
7 |
The torque converter stator temperature switch circuit indicates a hot mode when the transmission fluid temperature is greater than 140°C (284°F) for at least 15 seconds. Has the test run and passed? | -- | System OK |
