thorissr

Hello Everyone,

I've had a long week that I've dedicated to my 2006 CTTS and each time I fix one issue unfortunately I create another one. All in all it started with installing a aftermarket head unit when the next day my starter completely died and left me stranded. Since no local Indy wanted to take on the job of replacing my starter, I decided since I had the time why not do the job myself. Extracting the starter with metal coolant pipes was more tedious and time consuming than actually removing the intake manifold (1st time). Anyway, during the process of trying to jimmy the old starter out without messing dealing with the removal of the metal coolant pipes/thermostat etc., I managed to damage the knock sensor on bank 2 (driver side), cracked the H coolant line located inside the intake manifold, and nicked the rubber hosing/coupler that connects to the one large coolant pipe.

I was aware of the h coolant line and knock sensor during the process so I ordered parts and once they arrived I put everything back together. Unfortunately within 20 minutes after everything was back together and I fired her up, I had the unfortunate pleasure of experiencing Niagara Falls in my garage. I finally traced the massive leak and knew it was coming from the center back of the engine block. Off comes the intake manifold again when I discovered I eventually discovered the knick rubber hose. Ordered the neck but now I have to take the coolant pipes out to get to the lower large pipe. Researched on how to do this job and breaking it down went without error. However, after removing the plastic bracket that holds the 3 coolant pipes I noticed a white plastic T w/ 3 hoses located behind the plastic bracket. The clamps were badly corroded and rusted which I assume was the root cause of me having to top off my coolant occasionally. Headed to the parts store and purchased a similar sized metal T connection and swapped it out and put everything back together. I reused the old thermostat housing gasket since it was in good shape by resealing it and letting it sit overnight. Pressure tested it and no more waterfall effect or leaks.

All is good now, right? No!! A test drive revealed a tremendous decrease in power and sputtering. Back home I go and pull out the old handy Durametric to see what's going on. To my dismay codes indicated that the bank 1 knock sensor was the issue!! Regardless I knew I had to go back into the Belly of the V! Off she came and after examining bank 1 knock sensor I immediately noticed one wired had split off from the pigtail connector that clips into knock sensor. This part was hard to source and I learned that it's called a inductive transmitter sensor(955 606 381 01). Hopefully this helps someone out in the future. After getting it and installing it, one last inspection of the V and put everything back together AGAIN!

Whew!! What a week I thought. Now I can have a peace of mind that the 955 is in good shape and although many of the aforementioned issues were self-inflicted, I felt it was part of the learning process and I became more familiar with the vehicle, and my comfort level in doing work on it myself increased. Secret: On a scale of 1-10 I confess that I'm 3.5 as far as being mechanical savvy. If it isn't already put together and all I have to do is bolt it together, I typically take it to the shop. However since I have been off for the holidays I had time on my hands to break things.

Keep reading....did you really think that's all! Unfortunately this post doesn't end with a happy ending. After the last assembly and ANOTHER test drive the sputtering and loss of power is ten-fold. You know how the story goes, back home to assess. Hooked durametric up and it's now pointing me to cylinder 2 implausible issue where the injector isn't getting a signal. Popped the hood and inspected cylinder 2 connection when I noticed 1 wire came off from the connector that connects to the injector. I'm exhausted now, however, I muster up enough energy to source a Bosch connector at my local parts store. Wired everything correctly, put the multimeter to use and it's sitting at around 14.5V. Good to go you'd think but after another test drive cylinder 2 has become contagious and has spread its issue to cylinder 3! Checked coils packs...all good as expected since they were installed new earlier this year. For safe measure I purchased 8 new pre-gapped spark plugs and drop them in but the same issue exists.

Here's a copy and paste from Durametric:

Current Fault Codes

P0202

Cylinder 2 Injector Circuit - No signal/communication, test conditions are not-completed, fault is currently active and is not causing a DTC light

P0203

Cylinder 3 Injector Circuit - No signal/communication, test conditions are not-completed, fault is currently active and is not causing a DTC light

P0300

Random/Multiple Cylinder Misfire Detected - Value below lower limit value, test conditions are not-completed, fault is currently active and is not causing a DTC light

P0303

Cylinder 3 Misfire Detected - Value below lower limit value, test conditions are not-completed, fault is currently active and is not causing a DTC light

P0302

Cylinder 2 Misfire Detected - Value below lower limit value, test conditions are not-completed, fault is currently active and is not causing a DTC light

I've changed coils packs and spark plugs from other cylinders to 2 and 3 so I assume it's not the coil packs since the issue would follow to the new cylinder. I checked voltage at the injector and connector and they are all above 12 volts. It puzzles me as to why cylinder 2 and 3 aren't getting a signal when the multimeter indicates a solid current(connectors to injectors). I'm at my wits end and would appreciate anyone's assistance on other methods to assist me with wrapping this up. I'm headed back to work Monday and I won't have the time to dedicate to solving this afterwards, so any help to solve this last and final issue will help me maintain what little sanity I have. By the way, prior to the starter install my Cayenne ran flawlessly, other than a few quirks that were fixed easily. Also, I purchased a brand new battery when I purchased my new starter. So I don't expect electrical gremlins which could otherwise contribute to mysterious issues when the battery level is low or on its way out.

I apologize for the long post. I wanted to lay out everything that has transpired, and what I've done in hope that someone may be able to pinpoint something that I may have missed or broke to cause this issue.

Regards,

In Need of a Happy Ending to my Holiday

phatz

Are you enjoying the improved sound system?

Petza914

Since the two cylinders that are showing misfires are on the same bank of the engine, I'd look at things only specific to that one bank. The camshaft position sensor would be a good place to start. Do you have a Durametric or scan tool that will allow you to see live values for Bank 1 and Bank 2 camshaft deviation? See what those values are after the car has completed it's cold start protocol and the idle has dropped to normal. If the Bank where cylinders 2 and 3 are located shows a zero value for the camshaft deviation value, either that sensor has failed or the wiring to it has an issue and it could cause the runnability and misfire problems you're seeing.

v10rick

14.4V DC at the injectors indicates you have electrical continuity between the injectors and the engine controller.

That's a good thing BUT fuel injectors are powered by PWM (pulse width modulation) which must be diagnosed with an oscilloscope.

thorissr

Logs show Deviation didn’t change from cold to idle on Banks 1/2. Bank 1 logged -9.00 and 2 logged -5.00 upon start to idle and while driving.

Interesting that when I log “Uneven Running Cylinder” for all cylinders, all cylinders are registering activity @1034 units except for cylinders 2/3.

odd

thorissr

Quick update:

I managed to trace all faults that I was experiencing with Banks 2/3 misfires and the injector Circuit - No signal/communication errors on Banks 2/3. After retesting both injectors 2/3 and both connectors that clip into the fuel injectors with my multimeter, the common denominator was that both connectors weren't getting a signal from the wires coming out from the wiring harness that run parallel to the fuel rail. I began removing the insulation away from around the wiring and low and behold the injector connector wires were broken at about 2 inches leading back into the the wiring harness insulation. These wires were so brittle and aged from heat exposure that they actually crumbled when I handled them. I'm pretty confident that the breakage of these wires were a result of 14 years of immense engine heat exposure, coupled with me clipping and unclipping them multiple times in the past week.

I performed a quick fix by tracing the injector wires back past the break point and rewired them to new fuel injector connectors. Now I'm getting the correct voltage measurements to both fuel injectors and all fault codes were cleared and she's running like new! I will be ordering a complete wiring harness kit for all 8 injectors Monday since the current one is on its last leg, and I'm pretty sure this issue will rear its head again if not addressed with a new harness.

Hope this helps someone out in the future who may experience the dreaded cylinder Injector Circuit errors after coil packs/spark plugs/battery/knock sensors etc., have been ruled out during the process of diagnosing any variation of primary fault code(s) P0201 - P0208.

Regards,

A Happy Holiday Ending!

thorissr

Loving it now! I'm elated to finally rid the Cayenne of its outdated PCM 2.1 system. Having all the modern day amenities and electronic luxuries such as CarPlay/Android Auto all integrated with my steering wheel controls and projected on a 9" screen was well worth the price of admission.

Petza914

Congrats and nice work. I'm not sure why the wiring in these Cayennes is so crappy. The headlight harnesses experience the same type of brittleness issues where the insulation just flakes off.

thorissr

Thanks Petza914,

Funny that you mentioned the headlight harness...LOL! Two weeks ago I installed my Black Spyder Headlights and after installing them I began getting low beam and turn signal errors. Keep in mind these errors started immediately after installing the new headlights. Turned out to be a badly corroded headlight harness that was shot. Looking at it you''d think the car was in a major fire at some point. There was no way of rewiring that mess, so I ran down to my local Porsche dealership who happened to have new ones in stock. Hook it up and have yet to have another light problem.

But yeah, I'm now a firm believer that once you decide to upgrade/fix something on these older Cayennes, be prepared for oddities to arise only because of the deterioration of the parts Porsche decided to use in certain areas. This is my first Porsche and once I began maintaining it I was surprised in the parts they used when building these back then $100K + vehicles. There are proper places to utilize plastic and rubber parts, but to use them in areas where heat exposure will take its toll on them sooner rather than later really puzzles me.

Petza914

Wow, that's impressive, and not in a good way. I agree with you about plastic in hot environments. It's one of the reasons I changed my oil filter housing to a billet version from ECS tuning on my Cayenne and my daughter's BMW X5 and why on my 997s I use LN's spin on filter adapter so I can run a metal canister filter. Plastic just doesn't hold up as the esters release from the plastic over time from the heat and then it gets brittle.

CTTS520

Well done, thorissr! Your persistence paid off and thanks for helping the rest of us.

thorissr

Thanks CTTS520!

Only providing a small fraction of what I've personally learned and benefited from this Community over the past year. My persistence was mainly fueled by the plethora and broad amount of information provided within this forum.

deilenberger

Just a quick comment on injector testing. On most Bosch designed systems, the injectors receive positive power anytime the ignition is on. Since you were able to measure 14.5V with the engine not running, the Cayenne system must use this design. The injector is fired by taking the other connection to ground in the ECU. So you could measure 14.5V from the injector positive to ground, but you wouldn't measure any voltage if you read across the connector.

Glad to hear you have it solved! And yes - replacing the entire harness is a great idea...

thorissr

If I remember correctly I had to turn the ignition over to ACC (engine not running) to get a reading at the injector, however, the engine had to be running to register voltage at the injector wires that's part of the complete wiring harness. Also place a screwdriver up against the fuel infector while the engine was running, and then placed my ear right next to the screwdriver to hear the ticking sound emitted from the injectors which also confirmed that they were functioning.

Thanks

thorissr

...forgot to add that after driving around today everything is mostly okay after my initial fix the other day. However another code popped up on the Durametric where there's little information out there on the WWW as to what's causing it to stick. I've tried to clear the code but it's a persistent OBD code that won't clear, yet it's not causing a check engine light blinking or otherwise.

"P1206 - Positive Crankcase Ventilation Heater Output Stage- No signal/communication , test conditions are not completed. Fault is currently active and is not causing a DTC light."

I've searched around and definition/causes of this code varies by car manufacturer. Any idea or can someone point me in the right direction. I'm guessing this may be associated with a vacuum leak of sorts (Venturi Crankcase Breather Hose/Vent Line Breather Hose etc.) I noticed today that if I floor it and kick it into overdrive there's a sputter like hesitation during the RPM climb. It's not a sputter that I experienced with my recent misfires. Boost climbs and holds as expected. If I'm driving normally not pushing it, all if fine. This only occurs when I floor it. Think this can be associated with the code?




Any advice would be greatly appreciated.