Circuit Description
The automatic transmission fluid pressure (TFP) manual valve position switch consists of six pressure switches. Five of the switches are normally-open, and determine gear range selection. The sixth switch is normally-closed, and detects torque converter clutch (TCC) release fluid pressure. The TFP manual valve position switch also contains the automatic transmission fluid temperature (TFT) sensor. These components are combined into one unit, mounted on the valve body.
The PCM provides battery voltage on the three range signal circuits. By grounding one or more of the switches with fluid pressure from the manual shift valve, the PCM detects the selected gear range. When you disconnect the transmission electrical connector and the ignition is ON, the ground potential for three range signals from the PCM will be removed, and an invalid gear will be indicated. Refer to the Transmission Fluid Pressure Manual Valve Position Switch Logic table.
When the PCM detects any of the following conditions, DTC P1810 sets.
| • | An invalid gear state |
| • | A drive range after start-up |
| • | An incorrect gear ratio |
DTC P1810 is a type B DTC.
Conditions for Running the DTC
| • | The engine is running. |
| • | The system voltage is 8-18 volts. |
Conditions for Setting the DTC
One of the following three cases occurs:
Case 1
The gear range is illegal for 60 seconds (Refer to the Transmission Fluid Pressure Manual Valve Position Switch Logic table).
Case 2
| • | No VSS DTCs P0502 or P0503. |
| • | The engine speed is in transition from 0 RPM to greater than 600 RPM. |
| • | The vehicle speed is less than 3 km/h (2 mph). |
| • | D2, D4 or Reverse gear is indicated after start-up for 2 seconds. |
Case 3
| • | No TP DTCs P0121, P0122, or P0123. |
| • | No VSS DTCs P0502 or P0503. |
| • | No AT ISS DTCs P0716 or P0717. |
| • | No shift solenoid DTCs P0751, P0753, P0756 or P0758. |
| • | The TP is greater than 10%. |
| • | The vehicle speed is greater than 8 km/h (5 mph). |
| • | Engine torque is greater than 14 N·m (10 lb ft). |
| • | All of the above conditions are met and one of the following occurs for 5 seconds: |
| - | The TFP manual valve position switch indicates PARK/NEUTRAL when the gear ratio is less than 0.72:1 (4th gear). |
| - | The TFP manual valve position switch indicates REVERSE when the gear ratio is greater than 2.23:1, or less than 2.02:1. |
| - | The TFP manual valve position switch indicates D4, D3, D2 or D1 when the gear ratio indicates REVERSE. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met. |
| • | The PCM elevates line pressure. |
| • | The PCM assumes a D4 shift pattern. |
| • | The PCM freezes shift adapts from being updated. |
| • | The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records. |
| • | The PCM stores DTC P1810 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes. |
| • | A scan tool can clear the MIL/DTC. |
| • | The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring. |
| • | The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the PCM. |
Diagnostic Aids
| • | A pressure regulator condition could set DTC P1810. |
| • | Ensure the transmission linkage from the select lever to the manual valve is adjusted properly. |
| • | Inspect the connections at the PCM, the TFP manual valve position switch and all other circuit connecting points for an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
| • | Inspect the circuit wiring for an intermittent condition. Refer to Testing for Electrical Intermittents in Wiring Systems. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the indicated range signal to the manual valve range actually selected.
-
This step tests for correct voltage from the PCM.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain Diagnostic System Check? | -- | Go to Powertrain On Board Diagnostic (OBD) System Check (2.2L) or Powertrain On Board Diagnostic (OBD) System Check (2.4L) | |||||||
2 | Did you perform the Transmission Fluid Checking Procedure? | -- | Go to Transmission Fluid Check | |||||||
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 each selected transmission range match the Scan Tool TFP Switch display? | -- | Go to Diagnostic Aids | ||||||||
Does the Scan Tool TFP Switch A/B/C parameter indicate HI for all range states? | -- | |||||||||
5 |
Refer to Automatic Transmission Inline Harness Connector End View . Does the voltage measure ignition voltage at all three terminals? | -- | ||||||||
6 | Connect a fused jumper wire from terminal N of the J 44152 (signal circuit A) to ground while monitoring the Scan Tool TFP Switch A/B/C parameter. Refer to Automatic Transmission Inline Harness Connector End View . When signal circuit A (CKT 1224) is grounded, do any other signal circuits indicate LOW? | -- | ||||||||
7 | Connect a fused jumper wire from terminal R of the J 44152 (signal circuit B) to ground while monitoring the Scan Tool TFP Switch A/B/C parameter. Refer to Automatic Transmission Inline Harness Connector End View . When signal circuit B (CKT 1225) is grounded, do any other signal circuits indicate LOW? | -- | ||||||||
8 | Connect a fused jumper wire from terminal P of the J 44152 (signal circuit C) to ground while monitoring the Scan Tool TFP Switch A/B/C parameter. Refer to Automatic Transmission Inline Harness Connector End View . When signal circuit C (CKT 1226) is grounded, do any other signal circuits indicate LOW? | -- | ||||||||
9 | Test the signal circuits (CKTs 1224, 1225, and 1226) of the TFP manual valve position switch that did not indicate HI for a short to a ground between the PCM connector C1 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct a condition? | -- | ||||||||
10 | Test the signal circuits (CKTs 1224, 1225, and 1226) of the TFP manual valve position switch that did not indicate ignition voltage for an open between the PCM connector C1 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct a condition? | -- | ||||||||
11 | Test the affected signal circuits of the TFP manual valve position switch for a shorted together condition between the PCM connector C1 and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct a condition? | -- | ||||||||
12 | Test the affected signal circuits of the TFP manual valve position switch for an open or shorted condition between the AT inline 20-way connector and the TFP manual valve position switch. Refer to Circuit Testing in Wiring Systems. Did you find and correct the condition? | -- | ||||||||
13 | Replace the automatic transmission wiring harness. Refer to Transmission Overhaul in the 4T40-E/4T45-E section of the Transmission Unit Repair Manual. Did you complete the replacement? | -- | -- | |||||||
14 | Replace the TFP manual valve position switch. Refer to Pressure Switch Assembly Replacement. Did you complete the replacement? | -- | -- | |||||||
15 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming (2.2L) or Powertrain Control Module Replacement/Programming (2.4L) in Engine Controls. Is the replacement complete? | -- | -- | |||||||
16 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK |
