2007 Yamaha Apex Factory Service Manual, Page 614Get this manual

2007 Yamaha Apex Factory Service Manual, Page 614

FUEL INJECTION SYSTEM Er-1 Symptom No signal are received from the ECUEr-2 Symptom No signal are received from the ECU within
it Reinstated by Inspect the coupler for any pins that securelyturning the main may have pulled outCylinder identification
sensor coupler switch ONCheck the locking condition of the Main wiring harness ECU coupler couplerSub-wire harness coupler
Open or short circuit in wiring harness Repair or replace if there is an open or short circuitandor sub leadBetween sensor