2005 Ski-Doo Tundra, Skandic, Expedition Shop Manual, Page 354Get this manual
Section 06 ENGINE MANAGEMENT (4-TEC) Subsection 03 (COMPONENT INSPECTION AND ADJUSTMENT)
Test corresponding fuse, relay and wiringDisconnect the connector of the steering harnessMeasure the resistance of the BLUERED and LIGHT BROWN wires for Depress start button and the reading should change from to infinitely highRelease the start button and measure the resistor between LIGHT BROWN and BLACK wiresIt should be 50 Test continuity of circuit B-17If it is good, try new ECMOtherwise, repair harnessconnectorsTest continuity of circuit B-19If it is good, try new ECMOtherwise, repair harnessconnectors
SPARK PLUGS
Disassembly WARNING
Never remove ignition coil from the spark plug without disconnecting it from the wiring harnessFlammable vapors may be present in the engine compartment and ignited by spark which could cause an explosionDisconnect the wiring harness from the ignition coilRemove the ignition coilFirst unscrew the spark plug one turnClean the spark plug and cylinder head with pressurize air then completely unscrew