1992 MPV Check engine light

Please help. My check engine light is on and disconnecting the battery cable will not reset it. My husband ( a pretty good mechanic) has used the Haynes manual to troubleshoot it. He followed the directions completely (I double-checked). The light is supposed to blink to let him know where the problem is, but the light remained solid. Any suggestions would be greatly appreciated! Thanks in advance.
Kathy

i need help on this one too. someone reply

well if i had to guess i would say that yalls mpv's are around 80k or 160k miles.... that the service interval on the timing belt. it turns the check light on every 80k miles. you gotta pull the instrument cluster and theres a reset screw you gotta swap over behind it. getting the gear indicator set back in place and reading correctly in a pain in the ass lol