GROUNDWORK — Replace the Mazda transmitter battery Task: mazda-key-battery | Content version 2.0.0 Source page: https://csl-12-auto-repair.pages.dev/tasks/mazda-key-battery/ MODEL / APPLICABILITY [{"modelId":"mazda3-2017-us","market":"US","year":2017,"engine":"SKYACTIV-G 2.0 / 2.5 gasoline","configurations":["all","4-door","5-door","type-b-audio"]}] EXCLUSIONS Other model years and markets; imported Axela or diesel models; modified or aftermarket components with a different procedure. PREPARE [ ] Park in a safe place away from traffic. Work with the vehicle stationary, parking brake set and ignition off unless a step explicitly calls for a parked functional check. [ ] Does the original key match the auxiliary-key, battery-cap design on manual pages 6-38–6-39? [ ] Keep children and pets away from tools, fluids and coin cells. Never enter underneath the vehicle. [ ] Tape-wrapped flathead screwdriver [ ] Clear work tray [ ] One CR2025 cell or equivalent of the same type [ ] Insulating tape for the discarded cell terminals OBSERVE & RECORD Observation date: __________ Vehicle / equipment confirmed: __________ Record polarity, rubber-ring seating and the actual response from the reassembled transmitter. CR2025 marking and positive-up orientation: __________ Rubber ring and battery-cap condition: __________ Parked transmitter response: __________ | Choices: Responds; Intermittent; No response; Not tested Cover and auxiliary-key retention: __________ Before care: __________ STEPS 1. [ ] Press the release knob and remove the auxiliary key. Keep the car stationary and a working access key available. https://www.mazdausa.com/siteassets/global-resources/vehicle-resources/owner-manuals/2017/mazda3/2017-mazda3-owners-manual.pdf#page=451 | PDF page 451 2. [ ] Use a tape-wrapped flathead screwdriver at the point shown on page 6-38 to open the cover slightly, then insert it into the gap and work along the shown direction. Do not force the case. https://www.mazdausa.com/siteassets/global-resources/vehicle-resources/owner-manuals/2017/mazda3/2017-mazda3-owners-manual.pdf#page=451 | PDF page 451 3. [ ] Remove the cover, battery cap and old battery without touching circuitry or bending contacts. Keep the rubber ring intact; refit it if it detaches. https://www.mazdausa.com/siteassets/global-resources/vehicle-resources/owner-manuals/2017/mazda3/2017-mazda3-owners-manual.pdf#page=452 | PDF page 452 4. [ ] Install a matching CR2025 with the positive pole facing up. Refit the battery cap, close the cover and reinsert the auxiliary key. https://www.mazdausa.com/siteassets/global-resources/vehicle-resources/owner-manuals/2017/mazda3/2017-mazda3-owners-manual.pdf#page=452 | PDF page 452 https://www.mazdausa.com/siteassets/global-resources/vehicle-resources/owner-manuals/2017/mazda3/2017-mazda3-owners-manual.pdf#page=450 | PDF page 450 5. [ ] Test the buttons near the car. Insulate the old battery’s terminals and dispose of it under local rules; never crush it or put it in fire / water. https://www.mazdausa.com/siteassets/global-resources/vehicle-resources/owner-manuals/2017/mazda3/2017-mazda3-owners-manual.pdf#page=450 | PDF page 450 6. [ ] If the case, ring or response is not correct, arrange key inspection. Mazda recommends dealer replacement to reduce damage risk. https://www.mazdausa.com/siteassets/global-resources/vehicle-resources/owner-manuals/2017/mazda3/2017-mazda3-owners-manual.pdf#page=451 | PDF page 451 7. [ ] Record polarity, rubber-ring seating and the actual response from the reassembled transmitter. https://www.mazdausa.com/siteassets/global-resources/vehicle-resources/owner-manuals/2017/mazda3/2017-mazda3-owners-manual.pdf#page=451 | PDF page 451 DECISION CHECKS Does the original key match the auxiliary-key, battery-cap design on manual pages 6-38–6-39? Yes — ready for this check → Continue with the steps, stopping if the real component differs from the manual. Not yet / not sure → Preparation saved. Return when the condition is confirmed; leave the vehicle untouched. Different / damaged transmitter, corroded contacts or a damaged rubber ring → No response, case / ring damage or uncertain contacts: arrange transmitter service. How did the closed transmitter respond? Battery cap, ring and cover secure; button response restored → Is response repeatable with positive-up battery, ring and cover correctly seated? No response, case / ring damage or uncertain contacts: arrange transmitter service. → No response, case / ring damage or uncertain contacts: arrange transmitter service. I have only prepared the plan → Plan prepared; no physical maintenance result recorded. Is response repeatable with positive-up battery, ring and cover correctly seated? Response repeatable; ring and closure secure → Battery cap, ring and cover secure; button response restored The observation or repeat check is still incomplete → Plan prepared; no physical maintenance result recorded. Unreliable response, ring damage or loose closure → No response, case / ring damage or uncertain contacts: arrange transmitter service. RECHECK Does a repeat parked check still respond while the cover, cap and auxiliary key remain secure? After care: __________ Retest: not checked / improved / unchanged / worse If an earlier condition changes, reassess the later checks and result. RESULT CHECK How did the closed transmitter respond? Battery cap, ring and cover secure; button response restored Record only the result you actually observed. A saved web checklist is not confirmation that a vehicle has been repaired. Is response repeatable with positive-up battery, ring and cover correctly seated? Does a repeat parked check still respond while the cover, cap and auxiliary key remain secure? STOP CONDITIONS Different / damaged transmitter, corroded contacts or a damaged rubber ring No response, case / ring damage or uncertain contacts: arrange transmitter service. A part, label, connector or fastener differs from the cited manual; access requires raising the vehicle; you cannot identify the correct component. SERVICE HANDOFF Take the recorded observations, their dates and any actual work history to the service provider. No response, case / ring damage or uncertain contacts: arrange transmitter service. Notes: __________ SOURCES 2017 Mazda3 Owner’s Manual — Key Battery Replacement, printed pp.6-37–6-39 https://www.mazdausa.com/siteassets/global-resources/vehicle-resources/owner-manuals/2017/mazda3/2017-mazda3-owners-manual.pdf#page=450 | PDF page 450 Source checked 2026-10-04 Copyright retained by manufacturer; factual reference only. Original wording and schematic; no OEM images or manual redistribution. 2017 Mazda3 Owner’s Manual — Key Battery Cover Opening, printed p.6-38 https://www.mazdausa.com/siteassets/global-resources/vehicle-resources/owner-manuals/2017/mazda3/2017-mazda3-owners-manual.pdf#page=451 | PDF page 451 Source checked 2026-10-13 Copyright retained by manufacturer; factual reference only. Original wording and schematic; no OEM images or manual redistribution. 2017 Mazda3 Owner’s Manual — Key Battery Polarity and Rubber Ring, printed p.6-39 https://www.mazdausa.com/siteassets/global-resources/vehicle-resources/owner-manuals/2017/mazda3/2017-mazda3-owners-manual.pdf#page=452 | PDF page 452 Source checked 2026-10-13 Copyright retained by manufacturer; factual reference only. Original wording and schematic; no OEM images or manual redistribution. This blank plan records no completed maintenance or verified repair.