Hi,
Do you know if the scan that was done was able to communicate with the power steering control module? Was the CAN bus scanned?
Here is a video showing a can scan being done. CAN stands for controller area network. Basically, all computers/modules are tied together via a few wires. This type of scan will retrieve diagnostic trouble codes regardless of the module storing them. This is what needs to be done:
https://youtu.be/InIlnsjOVFA
As far as the system, here is how it works. In the event of a problem, the PSCM will enter one of two modes.
The EPAS (electronic power assist steering) enters reduced steering assist mode to protect the internal components of the EPAS (electronic power assist steering) when a concern is detected by the PSCM (power steering control module) such as low/high battery voltage or over-temperature concerns that are not considered to be a critical safety concern. This reduced steering assist mode gives the steering a heavier than normal feel.
The EPAS (electronic power assist steering) enters a manual steering mode (no electrical steering assistance is provided) when a concern that is considered to be a critical safety concern is detected. In manual steering mode, the vehicle has mechanical steering operation only, which gives steering operation a heavy feel.
As far as diagnostic trouble codes, there are more than one. However, in most cases, they will be a "B" type code.
Find out if the mechanic scanned the can-bus system. If he finds his scanner can't communicate with the PSCM, I attached the diagnostics below.
I hope something here helps. Let me know what you find or if you have other questions.
Take care,
Joe
See pics below.
Images (Click to make bigger)
SPONSORED LINKS
Tuesday, August 3rd, 2021 AT 9:42 PM