# Coincidence 81 error code after full charge with SDI battery? **URL:** \ **Category:** GEM Forum\ **Created:** [February 28, 2026, 3:26pm UTC](https://community.electricforum.com/t/coincidence-81-error-code-after-full-charge-with-sdi-battery/30205 "2026-02-28T15:26:48Z")\ **Posts on this page:** 2\ **Page:** 2
**Author:** ![dougl](https://avatars.discourse-cdn.com/v4/letter/d/b19c9b/32.png) [@dougl](https://community.electricforum.com/u/dougl)\ **Post date:** [March 3, 2026, 2:55pm UTC](https://community.electricforum.com/t/coincidence-81-error-code-after-full-charge-with-sdi-battery/30205/21 "2026-03-03T14:55:46Z")
> [@AssyRequired](#): > > @dougl - Your meter is pinned into the Red and Black wires at the MM harness? Initial tests were without the sensor connected so probing the red and black wires at the end of the harness and then at the end of the MM. The last test was done poking into the wires of the sensor associated with the red and black wires first with the MM connected and then without the MM. I have not pulled the speed sensor, which was my initial though, until I bypassed the MM and the speedometer then worked. ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [March 8, 2026, 9:14pm UTC](https://community.electricforum.com/t/coincidence-81-error-code-after-full-charge-with-sdi-battery/30205/22 "2026-03-08T21:14:38Z")
Good news everybody. Rip MM. It is dead. Power, 5v passes through but now output. I hope to find the time to solve the mystery. I had a couple slip through once with no pull-up resistor. Worked on my test jig but not in a car. Not the case here, as it isn’t working on the bench either. It will be good to open one up to look for corrosion. Ps. Need return address. [Previous page](https://community.electricforum.com/t/coincidence-81-error-code-after-full-charge-with-sdi-battery/30205.md?page=1)