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1 Keyfob Repair - Can't find schematic
2016 Toyota Rav4 keyfob failed. Can’t find a schematic. It does transmit, but very brief and weak signal. Capacitor? How do you determine values on micro capacitors on this board? https://fccid.io/GQ4-52T/Internal-Photos...
TRW Automotive, 314.4MHZ Transmitter
FCCID: GQ4-52T
Part Number: 226624-101 | 89071-0R040
Interchange Part Number: 1470A-33T
Battery Size: CR2016 (sold separately)
FCC ID: GQ4-52T
Board Marked: 226673-1 Rev C, Ref: Model: 226624-101, 226624-102
IC: 1470A33T, Canada IC: 1470A-33T
TRW Part No: 226624-101, 226624-102
Toyota Part No: 89071-ORO40, 89071-ORO20
Assembly Number 101 or 102
crwdns2934109:0crwdne2934109:0
crwdns2889612:0crwdne2889612:0
0
crwdns2944067:04crwdne2944067:0
Measurements can be done with multimeter, oscilloscope or something like the following tester:
BSIDE ESR02 PRO Transistor Tester SMD Components Checker Mega328 NPN/PNP Diode Resistor Inductor Capacitance ESR Meter
Check Amazon and other fine places for selection of different models, options etc
crwdns2934271:0crwdnd2934271:0 prop man crwdne2934271:0
It's likely bad or weak component and so tester not really helpful unless I know specs. New OEM transmitter is $190 and so I ordered a used OEM for $22 from Ebay as replacement that I can program into the car myself. The new $20 China knockoffs aren't worth a flip (tried that too). Thanks for your input.
crwdns2934271:0crwdnd2934271:0 uhf mhz crwdne2934271:0
Hi,
So there are no markings on the components then, even with a magnifying glass?
Here's a description of how it operates.
And here's info on the TDA chip
Not as good as a schematic but a start perhaps.
crwdns2934271:0crwdnd2934271:0 jayeff crwdne2934271:0
Thanks.... Using 20x jeweler's glasses and don't see any markings on the smaller components.
crwdns2934271:0crwdnd2934271:0 uhf mhz crwdne2934271:0