Circuit Description
The 3rd clutch pressure switch is located in the hydraulic passage to 3rd clutch. When oil pressure is supplied to the 3rd clutch, the switch is grounded, LOW. When oil pressure is not supplied, the switch is open, HI. The PCM receives the signal from the 3rd clutch pressure switch to detect the fluid pressure status, in order to reduce the shift shock upon shifting to 3rd gear, either from 2nd to 3rd or 4th to 3rd.
If the 3rd clutch pressure switch is OFF when the gear ratio indicated is 3rd gear, the PCM determines it as a fault and DTC P0848 sets. DTC P0848 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0848 Transmission Fluid Pressure (TFP) Switch 2 Circuit High Voltage
Conditions for Running the DTC
| • | No ECT DTCs P0116, P0117, P0118. |
| • | No VSS DTCs P0501, P0502, or P0503. |
| • | No TR Switch DTCs P0705 or P0706. |
| • | No AT ISS DTCs P0716, P0717, or P0718. |
| • | No Clutch PC Solenoid 1 DTCs P0746 or P0747. |
| • | No SS Valve Performance DTCs P0751, P0752, P0756, P0757, P0761, or P0762. |
| • | No Clutch PC Solenoid 2 DTCs P0776 or P0777. |
| • | No Incorrect Shift Pattern DTC P0780. |
| • | No Clutch PC Solenoid Electrical DTCs P0962 or P0963. |
| • | No Clutch PC Solenoid 2 DTCs P0966 or P0967. |
| • | No SS 1 DTCs P0973 or P0974. |
| • | No SS 2 DTCs P0976 or P0977. |
| • | No SS 3 DTCs P0979 or P0980. |
| • | No TAC DTCs P2101, P2108, P2111, or P2112. |
| • | No Minimum Idle Position DTC P2176. |
| • | No TCC PC solenoid DTCs P2763 or P2764. |
| • | No TCC Enable Solenoid DTCs P2769 or P2770. |
| • | The transmission is in D range 3rd gear for 2 seconds or greater. |
| • | System voltage is greater than 11 volts. |
Conditions for Setting the DTC
The 3rd clutch pressure switch is OFF when the transmission is in 3rd gear for 2 seconds or greater.
Action Taken When the DTC Sets
| • | The PCM illuminates the service vehicle soon (SVS) lamp. |
| • | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records. |
| • | The PCM stores DTC P0848 in PCM history. |
Conditions for Clearing the SVS lamp/DTC
| • | The PCM turns OFF the SVS during the third consecutive trip in which the diagnostic test runs and passes. |
| • | A scan tool can clear the DTC. |
| • | The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring. |
| • | The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM. |
Diagnostic Aids
| • | Inspect the connectors at the PCM, the transmission fluid pressure switch, and all other circuit connecting points for an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections . |
| • | Inspect the circuit wiring for an intermittent condition. Refer to Testing for Electrical Intermittents . |
| • | Inspect the 3rd clutch pressure switch for a disengaged connector. |
| • | Inspect the 3rd clutch pressure switch for an open circuit. |
| • | Inspect the 3rd clutch pressure switch for a stuck OFF condition. |
| • | Inspect for an internal fault of the PCM. |
Step | Action | Yes | No | ||||
|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |||||
2 |
Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the PCM. Does DTC P0848 run and fail? | Go to Step 3 | Go to Diagnostic Aids | ||||
3 |
Does the scan tool display LOW? | Go to Step 6 | Go to Step 4 | ||||
4 | Test the 3rd clutch pressure switch signal circuit for an open or a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 5 | ||||
5 | Inspect for poor connections at the PCM harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 7 | ||||
6 | Inspect for poor connections at the 3rd clutch pressure switch harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 8 | ||||
7 |
Important: Always perform the PCM set up procedure.
Did you complete the replacement? | Go to Step 9 | -- | ||||
8 | Replace the 3rd clutch pressure switch. Refer to 3rd Clutch Pressure Switch Replacement . Did you complete the replacement? | Go to Step 9 | -- | ||||
9 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | Go to Step 10 | Go to Step 2 | ||||
10 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | System OK |
