Diag Help Needed - ABS/PSM Workshop, Battery Appears "OK"

[deleted]

Hello,

 

I've researched the ABS/PSM workshop fault codes and most people say this indicates a failed/failing battery, but my battery appears ok. Attached are my current fault codes; below are details.

 

Appreciate any help or guidance that I can get.

 

Thanks,

Sheel

 

Vehicle and diag tools:

• 2005 Cayenne TT
• Enthusiast Durametric, Software 6.5.4.8

 

Fault Codes:

• Instrument cluster (1299, 429)
  • Not sure why these are being thrown
• KESSY (179, 180, 181)
  • I can confirm I'm having issues using my keyless entry - car does not respond to key fob clicks
  • Proximity sensors work
• A/C (2193, 1299)
  • Not sure why these are being thrown
  • My A/C is working as expected
• Windshield (1520)
  • My rearview mirror has fallen off and is currently disconnected
• Park Assist (1547, 437, 436, 1545, 1341)
  • not sure why these are being thrown, my park assist appears to be working as expected
• Seat Memory (1916)
  • I'll have to confirm, but I think my lumbar controls are working on the driver seat

 

Durametric:

• Cannot connect to the PSM module - communication errors
• Therefore, I cannot pull fault codes off the PSM
• I've contact Durametric for support, working with them but not sure if they will come through

 

Battery:

• NAPA Legend Premium AGM, 2.5 years old
• I was having battery issues and replaced it in 2/2015 - if I recall properly, I believe I was getting the ABS/PSM workshop faults prior to replacing the battery
• After replacing the battery I'm still having these fault codes
• Voltage appears ok -
  • Engine off, ignition/key "ON" position
    • multi-meter at the posts reads ~12.38
    • durametric reads ~11.8
  • Engine on
    • multi-meter at the posts reads ~14.13
    • durametric reads ~14.x

Fuses:

• I've checked #56, #38, #6 on the passenger side and they appear ok
• I've pulled #40 on the driver's side to reset the cluster

 

Symptoms

• ABS does not appear to be functioning
• Unclear if PSM is functioning
• Air suspension is functioning as expected

 

Head Unit

• I replaced the stock PCM2 with a Dynavin prior to the battery change
• I don't believe this unit is causing issues, but I will revert back to OEM to test

 

Brake Fluid Leak

• I have a leak that I have not been able to track down
• I believe it's from underneath the fluid reservoir - can smell brake fluid
• No signs of leaks on the ground or from the calipers
• Not sure if this would be related to the ABS/PSM workshop issues

 

short test.xps

Edited November 14, 2017 by deleted

[deleted]

Ok, couple quick updates -

• I replaced the Dyanvin with my OEM PCM 2 and it got rid of the gateway, PCM, park assist, and implausible signal faults (1299, 459, 01CB)
• ABS/PSM Workshop - I'm still getting the ABS and PSM workshop warnings on the instrument panel
• The Durametric still does not connect to the PSM 
  • Durametric has replied to me, acknowledging a known communication problem with 2005-2006 Cayennes, they have no solution yet
• Faults - left with the KESSY (179, 180, 181), A/C (2193), wipers (1520), and seat memory (1916)
  • Oddly, my KESSY is responding now - I can click the 'unlock' button to lock and unlock the CTT, however the 'lock' button doesn't do anything ... ???
  • Wipers is the same as above - disconnected rear view mirror because the glue failed
  • Lumbar is the same as above - lumbar works, including up/down  and in/out

Latest Durametric output attached.

 

Thanks,

Sheel

short test - OEM PCM.pdf

[deleted]

Ok, another update. Durametric has been working on a fix for the issue connecting to the PSM and they have a path release.

 

I was able to get the fault code, 1276 Hydraulic Pump. 

 

Is this referring to the brake booster? I have a brake fluid leak and can smell fluid from the area where the master cylinder/reservoir is, but the brake pedal does not drop to the floor. The fluid leaks only when I use the car, not if it's sitting a while, so I suspect the loss is driven by pressure. There is no visible sign of fluid on the ground or at the calipers.

 

Thoughts?

[JFP in PA]

50 minutes ago, deleted said:

Ok, another update. Durametric has been working on a fix for the issue connecting to the PSM and they have a path release.

 

I was able to get the fault code, 1276 Hydraulic Pump. 

 

Is this referring to the brake booster? I have a brake fluid leak and can smell fluid from the area where the master cylinder/reservoir is, but the brake pedal does not drop to the floor. The fluid leaks only when I use the car, not if it's sitting a while, so I suspect the loss is driven by pressure. There is no visible sign of fluid on the ground or at the calipers.

 

Thoughts?

 

No, it is not the brake booster.  ABS/PSM systems have their own hydraulic pump in the system, which is also one expensive bear, around $2K at retail (item #1):

 

[deleted]

Yikes. Thanks for the reply JFP. I've found some used pumps, but yes seems like hassle if that's what is failed.

 

My understanding is the ABS hydraulic unit is located on the passenger side of the vehicle, near the windshield behind the coolant overflow. Is that accurate?

 

Would a failing ABS hydraulic pump be a cause for loss in brake fluid?

 

Also, I'm going to check the PSM wires under the passenger carpet - what is the best way to pull the carpet back? I'm hoping not to have to cut the carpet.

[JFP in PA]

That is pretty much correct, the exact location varies a bit by model and equipment.  And no, a bad pump won't necessarily loose fluid.

 

You carpets should pull right up once the edge trim is removed.