The 3rd clutch pressure switch is located in the hydraulic passage to the 3rd clutch. When oil pressure is supplied to the 3rd clutch, the switch is grounded. When oil pressure is not supplied, the switch is open. 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, 2nd to 3rd, or 4th to 3rd.
If the 3rd clutch pressure switch is ON and the gear ratio indicates 4th gear, the PCM determines it is a fault and DTC P0847 sets. DTC P0847 is a type C DTC.
This diagnostic procedure supports the following DTC:
DTC P0847 Transmission Fluid Pressure (TFP) Switch 2 Circuit Low Voltage
• | No ECT DTCs P0116, P0117, P0118. |
• | No VSS DTCs P0501, P0502, or P0503. |
• | No TR Switch DTC 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 DTC P0776 or P0777. |
• | No Incorrect Shift Pattern DTC P0780. |
• | No 3rd Clutch Pressure Switch DTC P0848. |
• | 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. |
• | System voltage is greater than 10 volts. |
• | The transmission is in D range 4th gear for 2 second or greater. |
The 3rd clutch pressure switch is ON when the transmission is in 4th gear, for 2 seconds or greater.
• | 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 P0847 in PCM history. |
• | 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. |
• | 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 for a shorted transmission fluid pressure switch 2 circuit. |
• | Inspect for a transmission fluid pressure switch 2 stuck ON. |
• | 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 P0847 run and fail? | Go to Step 3 | Go to Diagnostic Aids | ||||
3 |
Does the scan tool display HI? | Go to Step 6 | Go to Step 4 | ||||
4 | Test the signal circuit of the 3rd clutch pressure switch for a short to ground. Refer to Testing for Short to Ground 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 |