Ignition Key Will Not Rotate Back to Off Position or Shift Lever Will Not Move Out of Park - keywords 4T40E 4T45E MN4 MN5 BTSI park lock solenoid switch transaxle

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.

This PI assists with diagnosing a condition of the ignition key will not rotate back to the off position or the shift lever will not move out of park.

If the ignition key will not rotate back to the off position, refer to the "Column/Ignition Lock Schematics" circuit in Electronic Service Information (eSI). The ignition lock cylinder solenoid, or park lock solenoid, is mounted underneath the ignition housing in the steering column and will allow the ignition key to rotate when not energized. The ignition lock cylinder solenoid is energized by closing the ignition lock cylinder control micro switch, which is located on the shifter mechanism. This micro switch is closed whenever the shift lever is in any gear position other than Park. In Park, this switch is open, the ignition lock cylinder solenoid is not energized, and the ignition key can then be rotated back to the off position. If unable to rotate the key to the off position, inspect the micro switch contacts for sticking closed, a short to ground in circuit 1601, or a mechanical concern with the shifter linkage allowing the switch to remain closed. The micro switch is serviced separately from the automatic shift lock actuator, or BTSI solenoid, which is also located on the shifter mechanism.

If the shift lever will not move out of the Park position, refer to the "Automatic Transmission Shift Lock Control Schematics" circuit in eSI. When the BCM receives a signal stating the brake pedal has been applied, the BCM will ground circuit 816 and energize the automatic shift lock actuator, or BTSI solenoid, which is located on the shifter mechanism. The shift lever can then be moved from the Park position. Use the Tech 2 scan tool and monitor the Shifter Unlock Command and Shifter Unlock Feedback status under Switch Inputs. If the command remains Off with the brake pedal applied, check for stop lamp switch input in the ECM or PCM data. If the command is On when the brake pedal is applied and no noise is heard from the solenoid, inspect for a blown BTSI fuse, an open in circuits 816 or 743, and terminal issues at the BCM, BTSI solenoid and left instrument panel fuse block. If no circuit issues are found, check for an open through the BTSI solenoid and replace as required. If no circuit or solenoid concerns are found and the proper brake switch input is present, replace the BCM and program per service information procedures.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

(2000-2005 Saturn L-Series)