2007 Accord 2.2 i-CTDi CN1 – Persistent P0602 and VSA warning light (66-01)

[draggore]

Hi everyone,

I've already started another thread about the P0602 fault alone, but since a few additional facts have come to light, I thought it would be better to start a new thread covering both issues together, hoping to make the discussion more visible and easier to follow. I hope this doesn't go against any forum rules.

I'm looking for some advice diagnosing an issue with my 2007 Honda Accord 2.2 i-CTDi (CN1).

The car has a persistent P0602 engine ECU fault, along with intermittent starting issues. I've also got the VSA warning light on.

Initially, I thought I'd simply be able to clear the VSA warning, but after scanning the VSA module with my Foxwell NT510 Elite, I discovered a permanent fault:

66-01 – Brake Pressure Sensor Failure

The fault comes back immediately after attempting to clear it.

I've read about the known issue with the internal brake pressure sensor in the VSA modulator affecting some 2005–2008 Accords.

However, given that I also have the P0602 fault and intermittent starting problems, I'm wondering whether there could be a common electrical issue.

A few questions:

• Could the P0602 and VSA 66-01 faults be related?
• Are there any particular wiring connections, plugs, grounds or power supply connections I should inspect? If so, could someone point me to their exact locations? I'm not particularly experienced with car repairs, so even basic directions (for example, behind which headlight, under the bonnet or behind the glovebox) would be very helpful.
• I've heard about a potentially problematic wiring connector behind the offside (right-hand) headlight on UK models. Could this cause ECU or VSA-related problems?
• Does fault 66-01 generally indicate an internal failure of the VSA modulator?
• Has anyone successfully repaired the original unit rather than replacing it?
• If I buy a used VSA modulator, does it need coding, or is calibration and the appropriate bleeding procedure sufficient?

I have a Foxwell NT510 Elite, which supports VSA calibration.

Any advice or first-hand experience would be greatly appreciated, particularly from anyone who has dealt with both P0602 and VSA 66-01 on the 2.2 i-CTDi.

Thanks in advance!

 

[draggore]

Additional information – VSA Live Data:

I've also checked the VSA module's Live Data.

The Brake Pressure reading stays at exactly 21.5, regardless of whether I press the brake pedal or release it.

However, the Brake Switch parameter changes correctly between ON and OFF when I operate the brake pedal.

Does this suggest that the brake pressure sensor itself has failed, or could this still be caused by a wiring, connector or power supply issue?

Would this be consistent with the known internal pressure sensor failure in the VSA modulator?

Any advice would be appreciated.

 

[F6HAD]

66-1 is a failed pressure sensor, you need to replace the modulator or have it rebuilt.

 

[draggore]

Thank you!
I spoke to a technician today, and he told me they don't want to do it because there's a chance the unit is vehicle-coded and they don't have the necessary tools. However, from the videos I've watched, it seems that these units are not coded, so I could try replacing it without needing to clone it.
Even if it is coded, I could remove the unit and send it away for refurbishment (or try soldering it myself if it's just a matter of broken connections).
If I can't find anyone to fix it at a reasonable price before the MOT expires, I'll get the MOT done anyway to find out whether there's anything else that needs fixing, and then declare the car SORN. After that, I can focus on fixing the VSA light issue and properly prepare the car for a future MOT.
In the worst-case scenario, I'll have to scrap it, which I'd really like to avoid.