You serious this is the first I read about a mainshaft sensor under the battery. I took to a tranny shop and they said it only had a vss and 2 solenoids. So I guess I will give it another try. Thanks I will report back soon.

 

"Sometimes" that sensor will get metal pieces on it causing issues. You can test it, then clean the end off and re-install. I suggest a new o-ring.

 

How do I test the mainshaft sensor and the countershaft sensor to see if they are working properly

 

Pull the sensor, clean w/ light oil, re-install and see if code goes away.

good luck

 

Ok so earlier today I pulled the sensor cleaned it and put new o ring. Put it back in and had the same problem. So I went to salvage yard and got a used sensor for $8 instead of a new one for$100 just to see if this would fix the the problem but it did not.

Currently I am dr ing the car with the top tranny speed sensor disconnected and the tranny shifts properly. If I connect it the tranny goes from 4th gear to 3rd gear by itself and gets stuck in 3rd.

 

Is the check engine light on w/ same code? You need to be precise, since we aren't there.

Suggest next checking continuity of wires from TCM to Mainshaft Speed Sensor. You will need a wiring diagram to follow this diagnostic and find the correct TCM connector to release.

Pull wire harness connector (D) at TCM and at sensor. Short one end and check resistance from other end of wires (orn/blu and wht/blu). Check should show a dead short. If open circuit, you have a wiring fault. If closed circuit, the fault is likely in the TCM. Time to find a used TCM and replace yours.

good luck

 

Is the tcm built into the tcu on the 95 accord because the tcu has already been replaced. Need to look for a wiring diagram to check wire continuity for mainshaft sensor.

 

TCM (Transmission Control Module) and TCU (Transmission Control Unit) are same component and this component is separate from the ECM or ECU on the 94-97 Accords.

You can download a shop manual from links in Online Manuals post in DIY forum. Look under Automatic Transmission section for wiring diagram.

It could be the MSS harness connector has a fault also, but the test described should identify that fault or wiring fault.

You should also measure the resistance of the MSS (should be 400-600 ohms) to verify it's good.

An alternate test that is better than shorting the MSS connector to verify wiring is to leave the connector hooked to MSS and verify that resistance of MSS is 400-600 ohms when measured at the TCM D connector. If you measure this resistance as good at the TCM D connector, then TCM is suspect even if it's been replaced.

good luck

 

Starting in 96, the 4-cylinder accord had a PCM (ECU and TCU combined into one). That was when the switched to OBD2.

I think that your 95 may have the PCM.

Pull back the carpet on the passenger side near the firewall. The PCM (or ECU and TCU) are bolted to a plate. Look for a Honda part number on a sticker like 37820-P0A-A51.

 

I pulled back the carpet on the passenger side and I only found the ecu. Where can I find the tcm so that I can check the wiring to the mainshaft sensor.

Part number under the carpet was 37820-poj-L51