B737 Undifferentiated or Other Model
Maintenance Airframe; Maintenance Powerplant
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance
Flight Crew Landed As Precaution; Flight Crew Diverted; General Maintenance Action; General Flight Cancelled / Delayed
Aircraft; Procedure; Manuals
I worked an inbound reverser log item on aircraft XXXX log page XXXXXXX. I pulled [aircraft maintenance manual] 78-XX-XX-XXX-XXX-XXX and [aircraft maintenance manual] 78-XX-XY-XXY-XXX-XXX.  Went out to aircraft and performed Engine Accessory Unit reset and then went to flight deck and cycled engine 1 reverser 4 cycles. Determined reverser was good and had no faults; signed off item. My maintenance manuals never had me go out to engine 1 to open fan cowls so fan cowls were never opened.
Maintenance Technician reported that aircraft maintenance manuals did not have a step to open fan cowls while working on thrust reversers.