For 1990-2009 cars
Automatic Transmission Components
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The TCM receives the throttle position from the ECM. This data is part of the PWM ECM Data Signal to the TCM. This signal processes in the TCM. Several parameter values that are contained within the PWM signal separate out. If the entire PWM signal is not present due to a circuit problem, DTC P1890 is set. If the TCM receives the signal, but the TCM determines that the TP value is invalid, this DTC will set.

### Conditions For Running The DTC

Tests continuously

### Conditions for Setting the DTC

The TCM receives the TP signal with a pulse width that is greater than 96 percent.

### Action Taken When the DTC Sets

• | The MIL/STL will not illuminate.

• | The TCM memory stores the DTC at the time of the first failure.

### Conditions for Clearing the MIL/DTC

• | A History DTC clears after forty consecutive warm-up cycles if no failures are present by this or any other non-emission related diagnostic.

• | The scan tool clears the MIL/DTC.

### Test Description

The number(s) below refer to the step number(s) on the Diagnostic Table.

1. Perform the TP sensor diagnostic table in Engine Controls.

#### DTC P1743 - TP Signal Invalid

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to DTC P0120 Throttle Position (TP) Sensor Circuit | Go to Powertrain On Board Diagnostic (OBD) System Check