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.
Tests continuously
The TCM receives the TP signal with a pulse width that is greater than 96 percent.
• | The MIL/STL will not illuminate. |
• | The TCM memory stores the DTC at the time of the first failure. |
• | 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. |
The number(s) below refer to the step number(s) on the Diagnostic Table.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- |