P1818
DTC P1810, P1816, or P1818
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P1810
- Transmission Fluid Pressure (TFP) Position Switch Circuit
DTC P1816
- Transmission Fluid Pressure (TFP) Valve Position Switch Indicates Park/Neutral (P/N) with Drive Ratio
DTC P1818
- Transmission Fluid Pressure (TFP) Valve Position Switch Indicates Drive without Drive Ratio
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The automatic transmission fluid pressure (TFP) manual valve position switch consists of three pressure switches. two of the switches are normally-open, and determine gear range selection. The third 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, attached to the control valve body. The transmission control module (TCM) provides a reference voltage on the two range signal circuits. By grounding one or more of the switches with fluid pressure from the manual shift valve, the TCM detects the selected gear range. Refer to Transmission Fluid Pressure Manual Valve Position Switch Logic (Transmission Fluid Pressure Manual Valve Position Switch Logic).
Conditions for Running the DTC
P1810
The engine is running for 5 seconds.
P1816
* No TP DTCs P0120 or P0220.
* No ISS DTCs P0716 or P0717.
* No OSS DTCs P0722 or P0723.
* No SS valve performance DTCs P0751, P0752, P0756, or P0757.
* No SS valve electrical DTCs P0973 or P0974, P0976, or P0977.
* The engine is running for 5 seconds.
* The Calc. Throttle Position is between 8 percent and 90 percent.
* The engine torque is greater than 50 Nm (37 lb ft).
* The output speed is 250 RPM or more.
P1818
* No MAP DTCs P0107 or P0108.
* No TP DTCs P0120 or P0220.
* No ISS DTCs P0716 or P0717.
* No OSS DTCs P0722 or P0723.
* No SS valve performance DTCs P0751, P0752, P0756, or P0757.
* No SS valve electrical DTCs P0973 or P0974, P0976, or P0977.
* The engine is running for 5 seconds.
* The Calc. Throttle Position is 10 percent or more.
* The engine torque is greater than 45 Nm (33 lb ft).
* The output speed is 153 RPM or more.
* The transmission fluid temperature is greater than 20°C (68°F).
Conditions for Setting the DTC
P1810
The TCM detects an invalid gear range for 60 seconds. Refer to Transmission Fluid Pressure Manual Valve Position Switch Logic (Transmission Fluid Pressure Manual Valve Position Switch Logic).
P1816
The TCM detects P/N with a drive ratio for 6 seconds.
P1818
The TCM detects a PARK, NEUTRAL, or a drive range with a REVERSE ratio for 3 seconds.
Action Taken When the DTC Sets
* DTCs P1810, P1816, and P1818 are Type B DTCs.
* The TCM commands maximum line pressure.
* The TCM freezes transmission adaptive functions.
Conditions for Clearing the DTC
DTCs P1810, P1816, and P1818 are Type B DTCs.
Diagnostic Aids
* Refer to Transmission Fluid Pressure Manual Valve Position Switch Logic (Transmission Fluid Pressure Manual Valve Position Switch Logic) for the normal range signals and the invalid combinations. On the table, LOW is 0 volts, HI is ignition voltage.
* Sediment in the valve body may cause improper operation of the TFP manual valve position switch. If sediment intrusion is suspected, clean the valve body and replace the TFP manual valve position switch.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Diagrams)
Connector End View Reference
* Component Connector End Views (Connector Views)
* Inline Harness Connector End Views (Diagrams)
Description and Operation
Electronic Component Description (Electronic Component Description) for automatic transmission fluid pressure manual valve position switch assembly information
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Special Tools
J 44152 Jumper Harness (20 pins)
Circuit/System Verification
1. Perform the Transmission Fluid Level and Condition Check (Transmission Fluid Level and Condition Check).
2. Engine idling, observe the scan tool TFP Sw. Sig. B/ Sig. C parameter while moving the gear shift lever from Park, to Reverse and through all the gear ranges and compare to the Transmission Fluid Pressure Manual Valve Position Switch Logic (Transmission Fluid Pressure Manual Valve Position Switch Logic) table. The parameter should match each gear range that is selected.
3. Observe the scan tool TFP Sw. parameter while moving the gear shift lever from Park, to Reverse and through all the gear ranges. The selected transmission gear range should match the scan tool TFP Sw. display.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Important: Additional DTCs may set when disconnecting the automatic transmission inline 20-way connector.
1. Ignition OFF, disconnect the X100 automatic transmission inline 20-way connector at the transmission.
2. Install the J 44152 on the harness side of the AT inline 20-way connector.
3. Ignition ON, engine OFF, observe the scan tool TFP Sw. Sig. B/ Sig. C parameter. The reading should display HI/HI.
• If not the specified value, test the appropriate signal circuit for a short to ground. If the circuits test normal, replace the TCM.
4. Install a 3 A fused jumper wire between the TFP B signal circuit terminal R and ground and TFP C signal circuit terminal P and ground. Verify the scan tool TFP Sw. Sig. B/ Sig. C parameters change from HI to LOW.
• If not the specified value, test the appropriate signal circuit for an open/high resistance. If the circuits test normal, replace the TCM.
5. Test the internal transmission wiring harness assembly TFP B signal circuit and TFP C signal circuit for a short to ground or an open/high resistance condition.
• If the circuits test normal, replace the TFP switch assembly.
• If a circuit is shorted or has an open/high resistance condition, replace the internal wiring harness.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.
* Wiring Harness Replacement (Service and Repair)
* Transmission Fluid Pressure Manual Valve Position Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for TCM replacement, setup, and programming.