Transmission Effects And Possible Causes:

Scenario 1)  - All PRNDL lights stay illuminated indefinitely in Park following a Key start.

1. Wrong Part Number PCM for application
2. TRS connector not plugged in
3. C1 through C4 (T1, T3, T41, or T42) circuits are open, shorted to ground, or shorted to 12 volts.
4. PCI bus failure (Open or shorted resulting in no communication to BCM or Cluster)
5. TRS
6. PCM
7. BCM

Scenario 2)  - "P" is indicated following a key start but all PRNDL lights illuminate in "N" following a shift from "R" to "N". If PRNDL lights illuminate in "N" and shifter is moved directly into "3" or "L" position without pausing in "OD", then the "OD" position shift schedule and electronic display will indicate "OD" until the shifter is shifted into the "OD" position and held for at least 3 seconds.

1. Worn Manual Lever (Rooster Comb). Check for heavy wearing of TRS switch contacts
2. Intermittent C1 through C4 (T1, T3, T41 or T42) circuits. Check for corrosion, terminal push-outs or spread terminals at PCM or TRS switch 10-way connector
3. TRS
4. PCM
5. BCM

Scenario 3)  - If an invalid code happens while operating in the "3" or "L" position, the "3" or "L" shift schedule and electronic display will be frozen (regardless of whether "OD", "3" or "L" is selected). The display will be frozen until the shifter is moved to the "N" position (all PRNDL lights will illuminate) and then back to the "OD" position. The "N" and "OD" position must be held for at least 3 seconds in each position to resume the normal "OD" shift schedule and electronic display.

1. Intermittent C1 through C4 (T1, T3, T41 or T42) circuits. Check for corrosion, terminal push-outs or spread terminals at PCM and/or TRS connector
2. TRS
3. PCM
4. BCM

These same symptoms may occur without the code P0706(28) getting set. It is possible that the invalid code that was sensed by the PCM only occurred once or twice during the given ignition key start and/or did not last for longer than 0.1 second.

Name of code: P0124(29) - Throttle Position Sensor/APPS Intermittent 

Name of code: P0122(2A) - Throttle Position Sensor /APPS Low 

Name of code: P0123(2B) - Throttle Position Sensor /APPS High