997 C2 tiptronic General Failure. CAN bus problem.

[tkacki]

Hi

Car is 997C2 tiptronic my'05. No start.

Symptoms:

1. No cranking.

2. PSM failure, PASM failure, ABS failure messages appears on instrumet display.

3. Tiptronic selector lever indicator works fine when ignition key in accessory position (shows lever position).

4. Tiptronic selector lever indicator in instrument cluster dissapears 2 seconds after swithing ignition on, right after first failure message aprreas (PSM fail).

PIWIS:

1. No communication with tiptronic control unit. Tester is not able to find the module. Module has been replaced with new one - no help. Module has power.

2. Fault codes in all modules related to communication with other modules. No communication with DME and transmission is common fault.

3. CAN GETAWAY stores C111 "CAN drive" fault / "open circuit" - cannot be erased.

4. DME stores failure CAN getaway "A" fault.

I think tiptronic control unit has separate CAN bus directly to DME and is not connected to the gateway.

Any ideas ?

Thanks.

Edited August 22, 2009 by tkacki

[wvicary]

Can you communicate with all others modules? Any modifications done to the vehicle?

[RFM]

There was a service action for 997 MY 05 about a year ago concerning water integration in the inner foot well area, left behind the fuse box and in the same right side area (wiring and connectors). Also on the plastic covers, located in the battery room, far left under the interior filter and far right under the wiper mechanism, the gateway + connector is attached on the bottom of the cover right and could be corroded, i would take a look to be sure.

[RFM]

Sorry correction, far left under the wiper mechanism and far right under the interior filter.

[tkacki]

Thanks for Your responses.

No mods. Car has visited a number of workshops resulted in unsuccessful repairs. POSIP was replaced.

PIWIS is able to communicate with all modules except Tiptronic. However, comunication with airbag (POSIP) and PSM is not stable. Somtimes PIWIS losts communitation

with those two modules (i am able to read/clear faults, read actual values, etc. but with random disconnections).

GATEWAY is fine. No signs of water. Plug and socket are also fine.

[Loren]

Have the battery checked for both load and specific gravity.

[tkacki]

Battery is new and fine. I excluded battery problems.

Diagnosis gives same results even when charger is connected to the vechicle.

[PAULSPEED]

Maybe you could hotwire the starter.

Paul

[tkacki]

No problem to hotwire the starter - I tried to bypass the starting relay and engine cranks.

IMHO the problem is electronics. The key to repair is to enable communication with Tiptronic module.

[tkacki]

Additional questions:

1. In a standard, 100% functional 997, is it possible to connect to tiptronic module using PIWIS or maybe it requires to connect directly to tiptronic CU's CANL / CANH lines ?

2. Engine NOT running, ignition ON. Can You see indication of tiptronic selector lever position in instrument cluster ? Does LED indicator follows movement of selector lever ?

Edited August 24, 2009 by tkacki

[RFM]

1/ PIWIS have " Fault finding program " and "Electrical diagram " as features, use that to find out what's wrong.

2/ Yes.

[PAULSPEED]

It is good to know that the car cranks. Sounds

like the car will not fire up and idle. I would put a timing light

on one of the spark plug wires to see if you are getting

sparks to your plugs.

Paul

[RFM]

Was this morning in the Porsche workshop and took a closer look concerning your problem, the selector lever indicator on the dash lights up, in all the positions P R etc., controlled by the gearbox switch, the gears 1 2 3 4 5 and manual possition, in contrary stays out, controlled by the control box. They told my about some faulty Tiptronic control boxes, which they have changed out. Hope it helps.

[tkacki]

Thanks for Your answers and help.

"Fault finding program" - Yes, I know it. It's usless in this case. It detects over 50 faults (communication) in many CU's but highlights tiprtonic module as missing.

Spark - I can bypass starting relay and enforce engige to start, but this is not a repair, just check. The problem is that tiptronic module prevents engine from cranking (via relay) . The instrument gauge shows message "press brake", and "select "P" or "N" to start" regardless ow what You do, as it has no communication with tiptronic module. The fun is that the tiptronic module is NEW and I am not able to connect to it to check it / code it.

[RFM]

Is the car 100% stock, no mods done, engine or gearbox swap (from manual to Tipronic) and free of accidents?

[tkacki]

Car is stock. No mods. No swaps.

Car had serious accident.

[RFM]

I fear that a close wiring and connector check is inevitable (visually and with multi-meter) in case of an accident, especially in the affected areas and even the full length of the wires if necessary, an electrical diagram will be needed. It can take a while but is soluble, success.

[RFM]

Don't forget to check the brake light switch, wiring and fuse box first to eleminate PSM/PASM/ABS codes and cranking problem.