Yamaha GP1800R: SCU Fault and SCU Initial Learning

The GP1800R's SCU controls shifting. If it reports faults or was replaced, M-JET DIAGNOSTIC is the tool with which you read the messages and start the initial learning.

What you do

• Read SCU codes 157 to 164 in the fault memory
• Look at RPS signals and shift angle in the live data
• Check connectors, ground and power supply
• After replacing the SCU, start the initial learning in the app

Check for a shared cause

If several SCU codes occur at once, a shared trigger is often responsible: voltage, connector or ground. Check these first before you consider the SCU defective. Initial learning is meant for the case that the unit or sensor was replaced and fixes no mechanical problems on the drive. Only work on the craft when it is secure and the pump cannot spin freely. Known from forums: messages about the reverse gate (such as code 159) repeatedly had mundane causes, for example a tie-down strap stretched across the stern eyes, a slightly bent rod, the connector at the main RiDE harness, or relay and fuse. Check this by hand with the engine off, then clear the memory and read it again.

Related topics

• Yamaha GP1800R: Cruise and No-Wake Switch Not Responding (Code 68)
• Yamaha GP1800R: Knock Sensor (Code 17) at Full Load
• Yamaha WaveRunner SCU Initial Learning (RiDE)
• Diagnostics and fault codes for your Yamaha model
• All Yamaha WaveRunner diagnostics topics

Everything runs via app over Bluetooth, for Yamaha WaveRunners from model year 2002 to today. Learn more about the M-JET DIAGNOSTIC for Yamaha WaveRunner.