[SWRT]

i had my engine light and eps light come on.i took it to the dealership and they said there was the speed sensor that went bad.They said it takes thw speed from the ground and send it to the ECU.so the ecu 'locked' the steering wheel.

The EPS ECU takes VSP (vehicle speed) from the CAN bus... its the same signal that is shared with the speedo and engine ECU.

When the EPS ECU loses the VSP signal, it should not be killing assist. In fact, it switches to using the RPM signal for the assist map... so the steering actually gets lighter.

If you lost EPS assist, then there was more going on than just a missing VSP signal.

SWRT

 

[SWRT]

For the members getting an EPS light and loss of assist, your dealers are still able to pull the codes, they just don't seem to know how to work the HDS (Honda Diagnostic Scanner).

The EPS system has two levels of faults. Both throw an EPS light.

Level 1 failsafe occurs when the EPS ECU loses communication with the CAN bus. The steering feel changes (gets lighter) but does not stop assist.

Level 2 failsafe occurs when the EPS ECU either gets conflicting signals from the torque sensor (on top of the rack), when it senses abnormal motor currents, when it senses low voltage from the car (below 9V), or when it detects a motor resolver fault.

The latter seems to be what most people are experiencing. There isn't really anything you can do other than take it to the dealer. If the light is off, the dealer needs to hook up the HDS and go into the EPS menu. They will need to pull the historical codes. EVERY TIME the EPS light comes on a code is stored. Multiple codes are visible, but the freeze data exists only for the last Level 2 code. Freeze data is everything the EPS ECU knows at the time of fault... Throttle, Gear, Speed, Engine Temp, Steering Torque, Battery Voltage...

If your dealer hooks up the ECU properly, the next time they dock the HDS the data will be automatically uploaded to American Honda, where engineers can access it.


Other than that, I know there have been issues with EPS harness damage due to heat from aftermarket headers... but given the number of people complaining I doubt this is whats happening.

There have been occurrences of the EPS ECU not having a good ground. The ECU is mounted at the bottom of the A-Pillar on the passenger side... right beside the passengers feet. If you pull that cover off, the EPS ECU is the 6x6" silver box mounted on a bracket. It has some pretty heavy gauge wires going to it. The ECU ground is the smaller black wire that is screwed to the sheet metal (above the box I think). If the factory f'd up and didn't use a paint cutting ground bolt... the ground is weak and can cause intermittent level 2 faults... the ECU would log these as voltage faults.

Another possible cause is low battery voltage... which makes sense at extremely low temperatures. The battery voltage drops considerably during starting... if it goes below 9V the EPS ECU will trip out.

Thats all I got guys, get to a dealer and pull those historical codes. Honda engineering will be able to see it and a TSB can be issued once the root cause is sorted.

SWRT