Mercury V8 250

Possible Causes
• Wiring problem
• Mechanical issue in gearcase
• Failed shift actuator
Summary of Fault Correction Possibilities
• Inspect the wiring to the shift actuator, repair as needed.
• Inspect the gearcase for proper shifting.
• Replace the shift actuator.
ShiftPos2_RangeLow
Fault Type:
Horn: Guardian: UFC: Transmission to Helm: Freeze Frame Priority:
Sticky Critical 50% 1023‑25 Yes 2
Explanation
The secondary shift position encoder in the shift actuator does not appear to be working properly; the PCM received a signal
that is below the valid limit. Power is limited to prevent engine damage.
Possible Causes
• Wiring problem
• Failed shift actuator
Summary of Fault Correction Possibilities
• Inspect the wiring to the shift actuator, repair as needed.
• Replace the shift actuator.
ShiftPositionSensor_Diff
Fault Type:
Horn: Guardian: UFC: Transmission to Helm: Freeze Frame Priority:
Sticky Critical 100% 1024‑6 Yes 4
Explanation
The shift position sensors located in the shift actuator do not agree.
Possible Causes
• Wiring problem
• Faulty shift actuator
Summary of Fault Correction Possibilities
• Inspect the shift actuator wiring, repair as needed.
• Replace the shift actuator.
Shift_XCheck_Diff
Fault Type:
Horn: Guardian: UFC: Transmission to Helm: Freeze Frame Priority:
Sticky Critical 5% 4002‑6 Yes 4
Explanation
The command module is not equal to the PCM in cross‑check of shift position.
Possible Causes
• Incorrect DTS system configuration
• Faulty command module or PCM
• Wiring problem
Fault Codes
Page 4A-38 © 2018 Mercury Marine 90-8M0146617 eng JULY 2018