Circuit Description
The control module controls the shift lamp using the following inputs:
| • | The Engine Coolant Temperature (ECT) sensor |
| • | The Throttle Position (TP) sensor |
| • | The Vehicle Speed sensor (VSS) |
| • | The Engine RPM |
The control module uses the measured RPM and the vehicle speed in order to calculate what gear the vehicle is in. This calculation determines when the shift lamp should be turned ON.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | |||
2 |
Is the shift lamp ON? | -- | ||
3 |
Is the shift lamp ON? | -- | ||
4 | Using the scan tool, command the shift lamp OFF and ON. Does the shift lamp respond to the scan tool command? | -- | System OK | |
5 | Check the terminal connection at the PCM electrical connector for the shift lamp control circuit. Was a problem found? | -- | ||
6 | Check for an open in the shift lamp circuit and repair as necessary. Was a repair necessary? | -- | ||
7 | Check the IPC for for a malfunction, Refer to the Instrument Panel portion of the service manual. Is the action complete? | -- | -- | |
8 | Repair as necessary. Is the action complete? | -- | -- | |
9 |
Is the shift lamp ON? | -- | ||
10 | Repair the short to ground in the shift lamp control circuit. Is the action complete? | -- | -- | |
11 | Replace the PCM. If the PCM is malfunctioning, the new controller must be programmed. Is the action complete? | -- | -- | |
12 | Operate the vehicle within the conditions under which the original symptom was noted. Does the Shift light operate properly? | -- | System OK |
