Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P0989: Transmission Fluid Pressure (TFP) Switch 5 Circuit Low VoltageDTC P0990: Transmission Fluid Pressure (TFP) Switch 5 Circuit High Voltage
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
TFP Switch 1 Signal | P0842 | P0843 | P0843 | -- |
TFP Switch 3 Signal | P0872 | P0873 | P0873 | -- |
TFP Switch 4 Signal | P0877 | P0878 | P0878 | -- |
TFP Switch 5 Signal | P0989 | P0990 | P0990 | -- |
Typical Scan Tool Data
Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|
Operating Conditions: Engine running, normal operating temperature Parameter Normal Range: 12 Volts = Hi, 0 Volts = Low | |||
TFP Switch 1 | Low | Hi | Hi |
TFP Switch 3 | Low | Hi | Hi |
TFP Switch 4 | Low | Hi | Hi |
TFP Switch 5 | Low | Hi | Hi |
Circuit/System Description
The transmission fluid pressure (TFP) switch 5 is part of the control solenoid (w/body and TCM) valve assembly and is not serviced separately. The TCM supplies 12 volts to the TFP switch 5 on the TFP switch 5 signal circuit; the TFP switch 5 has an internal case ground. TFP switch 5 is normally closed, Low. When oil pressure is present at the TFP switch 5, the switch is open, high. The normally low clutch pressure control (PC) solenoid 4 controls the transmission fluid to the 1-2-3-4 clutch. The TCM monitors the normally closed TFP switch 5 signal circuit to determine the 1-2-3-4 clutch status.
Conditions for Running the DTC
| • | No DTCs P0120, P0711, P0712, or P0713. |
| • | No DTCs P0965, P0966, P0967, P0968, P0969, P0970, or P0971. |
| • | No DTCs P0973, P0974, P0976, P0977, P2719, P2720, P2728, P2729, or P2730. |
| • | No DTCs P1825 or P1915. |
| • | Ignition voltage is between 11-15 volts. |
| • | The transmission fluid temperature (TFT) is 20-150°C (68-302°F). |
Conditions for Setting the DTC
P0989
The TCM detects that the TFP Switch 5 signal voltage remains low, 0 volts when the low and reverse clutch or the 4-5-6 clutch is commanded ON, then the TCM sets DTC P0989.
P0990
the TCM detects that the TFP Switch 5 signal voltage is high, 12 volts when the low and reverse clutch or the 4-5-6 clutch is commanded OFF, then the TCM sets DTC P0990.
Action Taken When the DTC Sets
| • | DTCs P0989 and P0990 are Type C DTCs. |
| • | The TCM freezes transmission adaptive functions. |
Conditions for Clearing the DTC
DTCs P0989 and P0990 are Type C DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
If there are any other transmission related DTCs set, diagnose those DTCs first.
Circuit/System Testing
- Ensure the TFT is near the temperature displayed in the Failure Records.
- Start the engine and place the transmission range selector in D6.
- Observe the TFP Switch 5 parameter while commanding 1st gear and then commanding 2nd gear with the scan tool. The TFP switch 5 should transition from low in 1st gear to high in 2nd gear.
| ⇒ | If the TFP Switch 5 parameter state does not change, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection. |
| ⇒ | If no concerns are found, replace the control solenoid (w/body and TCM) valve assembly. |
Component Testing
Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection.
Repair Instructions
Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control solenoid (w/body and TCM) valve assembly replacement. Refer to Control Module References for replacement, setup, and programming.
