• Gearcase stuck in gear
• Failed shift actuator
Summary of Fault Correction Possibilities
• Reconfigure the DTS system.
• Replace the command module or PCM.
• Check the helm wiring.
• Check the gearcase for free shifting.
• Replace the shift actuator.
SPI_CrosscheckData_SOH
Fault Type:
Horn: Guardian: UFC: Transmission to Helm: Freeze Frame Priority:
Nonsticky Critical 5% 4016‑6 Yes 4
Explanation
There is a communication problem with the SmartCraft control system.
Possible Causes
• Internal engine PCM error
Summary of Fault Correction Possibilities
• Replace the PCM.
StbdECT_Overtemp
Fault Type:
Horn: Guardian: UFC: Transmission to Helm: Freeze Frame Priority:
Nonsticky Critical 5% 521‑20 Yes 4
Explanation
The engine appears to be overheating; the PCM received a signal from the engine coolant temperature (ECT) sensor that is
higher than normal.
Possible Causes
• Restricted cooling water flow
• Restricted thermostat
• Degraded water pump impeller
Summary of Fault Correction Possibilities
• Check for cooling system blockage.
• Inspect the thermostat.
• Inspect the water pump impeller.
StbdECT_RangeHigh
Fault Type:
Horn: Guardian: UFC: Transmission to Helm: Freeze Frame Priority:
Nonsticky Caution 100% 521‑24 Yes 2
Explanation
The engine coolant temperature (ECT) sensor does not appear to be working properly; the PCM received a signal that is above
the valid limit.
Possible Causes
• Wiring problem
• Defective sensor
Fault Codes
90-8M0146617 eng JULY 2018 © 2018 Mercury Marine Page 4A-39