Mazda capella s/w 1999 automatic,chassis gw8w hold light flashing.According to the 1st transmission company said speed sensor or related cct faulty so they changed the speed sensor and it did not solved the problem,replaced another sensor...same,replaced the computer on the car sitll the same said electrical fault.took it to 2nd transmission company and they said speed sensor faulty,replaced that and fault still the same.Advised me that 1st gear is slipping and they opened the pan at the bottom and said transmission never been serviced before becz it had a factory seal attached and metals mixed with fluid advised to replace transmission which they coated was really high.sourced a 2nd hand transmission and my mechanic replaced it with the faulty one which solved the gear slipping problem.Hold light still flickering so he drained the trans fluid at home and replaced the filter found bit of metal on the pan.Still hold light flickering also noticed rmp meter flickes slightly when you stop.

Optional Information:
Year: 1999
Make: Mazda
Model: capella
Engine: FP-524043
HELP..