Definition of Terms

Definition of terms

Warm-up cycle

The warm-up cycle is the time which the engine requires to reach operating temperature. To fulfil the 'warm-up cycle' condition, the engine temperature on start-up must not be higher than a specified value (currently 44 °C). The engine operating phase has to be long enough to produce a certain temperature increase (currently 21 °K, but the temperature reached must be at least 54 °C). The warm-up cycle condition is needed to decrement (count down) the fault erasing counter in the event of faults that have been recognized as "healed".

Driving cycle

A driving cycle consists of starting the engine, possibly a test drive (with a share of idling, partial load, constant driving, and overrunning phase) and the time between stopping the engine and starting again. For the purpose of shedding/healing faults, the driving cycle must sometimes include performing the relevant diagnosis.

Ready status

The "Ready Status" menu item indicates whether the OBD system has performed the required fault checks since the last time the 'fault memory was erased' or 'reset'. If a check proves to be OK, the one-off check is sufficient for a Ready status; if the system is faulty, the Ready status is achieved after a second check.

This is important, for example, for Inspection and Maintenance; this is where it is possible to detect whether the fault memory of a faulty vehicle was erased before the examination, without the cause(s) of the fault having been remedied.

The ready status is displayed for the following sub-systems:
- Oxygen sensor heater
- Oxygen sensor
- Secondary-air system
- Fuel tank ventilation system
- Cat. conv. efficiency

Once the Ready status has been reached for a sub-system, this is stored until the next time the 'fault memory is erased'.

NOTE:
- in some countries (currently: USA, Canada), it is necessary to restore the Ready status following manipulation of the DME before the vehicle is supplied to the customer.
- To do this, you must perform the short test available in the 9588 Porsche System Tester II or a test drive to achieve the relevant diagnostic conditions (these are listed for each system at the beginning of the test instructions for P codes in this manual).
- If you have any questions, please contact your nearest importer.

Freeze frames (officially prescribed 'frozen fault boundary conditions')

Freeze Frame data is standardized and records the operating conditions in the (first) event of a fault. Freeze frames have different priorities. This can be significant when output to a scan tool since it may only be possible to display one freeze frame here although several faults are stored (misfire or fuel supply faults overwrite the freeze frames of other faults).

Freeze frames can be examined in the "extended fault memory" of the 9588 Porsche System Tester II.

The control module must be able to output the following freeze frame data to a standardized diagnostic device (scan tool):
- DTC that caused this freeze frame to be stored
- Engine load
- Engine speed
- Coolant temperature
- Oxygen sensor status (control or sensing)
- Mixture adaptation values
- Fuel pressure (when available, not for DME 7.1.1 at present)
- Intake manifold pressure (when available, only for turbo vehicles at present in the case of DME 7.1.1)
- Vehicle Speed

With DME 7.1.1, a freeze frame is stored whenever a fault occurs for the first time. This freeze frame contains all the actual values listed above.

Other ambient conditions

Each time a fault occurs, two other operating conditions (actual values at the time the fault occurred), as well as the operating time and even the total number of kilometers/miles, are stored in DME 7.1.1.

This includes one memory entry for the first occurrence of the fault (the entry is stored) and a further entry for the last occurrence of the same fault (the entry is updated each time the fault recurs). This data can provide troubleshooting clues for difficult diagnoses, and can only be examined in the "extended fault memory" of the 9588 Porsche System Tester II. The list of possible ambient conditions overlaps at present with the freeze frames in order to store important ambient conditions even after the first occurrence of the fault.

Fault shedding (confirmation of a suspected fault)

When a fault occurs for the first time during a diagnostic routine, it is stored as a suspected fault. At the same time, a fault shedding counter is started that contains a certain value (e.g. 2). During additional diagnostic procedures, the shedding counter will be decremented by 1 if the fault is recognized in the same area window. When the shedding counter has reached the value 0, the fault is considered as shedded and is thus entered. If the fault class provides for this, the CE light is now activated as well.

Fault healing (CE light off)

When a fault occurs for the first time during a diagnostic routine, it is stored as a suspected fault. This suspicion is either confirmed (the fault occurs again) or refuted (the fault does not occur again, no display on a scan tool) in the subsequent driving cycle. If the fault activates the CE light, a fault healing counter that contains a certain value (e.g. 5) is started at the same time. During additional diagnostic routines, the fault healing counter will be decremented by 1 if the fault is not recognized in the same area window. When the fault healing counter has reached the value 0, the fault is considered to be healed. If the fault has triggered the Check Engine light, then the latter is switched off as long as this is not prevented by any other faults. The fault remains in the fault memory for the time being; it is not deleted again until a certain number of warm-up cycles (defined in the fault erasing counter) are completed successfully (as workshop help, e.g. if the tank cap is not screwed on tightly for a short time).

Fault erasing counter

For each recognized fault, an individual fault erasing counter is kept. It contains the defined number of required OK tests until the respective fault is erased in the fault memory.

The first time a fault is recognized, the fault erasing counter is set to 80, for example (suspected fault).

If an unshedded fault is recognized as healed, the fault erasing counter is set to 10 (only visible for the PST2). (Workshop help for very sporadic faults)

Each time a shedded fault is recognized (= CE light on), the fault erasing counter is set to 40, for example. It retains this value until fault healing is recognized.

The fault erasing counter is decreased by 1 after each warm-up cycle if the fault in question is recognized as unshedded or healed. When the fault erasing counter reaches the value 0, the fault is erased from the memory. Faults that are confirmed but not recognized as healed are not decremented in the fault erasing counter.

Fault frequency counter

This indicates how often a fault has recurred after its first occurrence. If the value is "1", the fault has occurred only once. Thus, it can now be "present" or "not present". The number in the fault frequency counter is increased by 1 whenever the fault status changes from "not present" to "present". A large value in the fault frequency counter thus might indicate a loose contact. It is important to remember that the ambient conditions stored in the "extended fault memory" relate only to the first and last occurrence of the fault.

Warnings

DANGER:
- Danger of accident if test and diagnostic equipment (PST2, scan tool, etc.) is operated while driving.
- Always get a second person to operate the test and diagnostic equipment while driving
- Some tests or system checks can affect vehicle handling so make sure to carry out these tests in a cordoned-off area.
- Gasoline is toxic.
- Inhaling vapors can lead to irritation of the mucous membranes and eyes
- It represents a serious risk to health when inhaled, touched or swallowed over extended periods
- Wear a breathing mask with active charcoal filter; do not breathe in any fuel vapors
- Wear protective gloves that are fuel-resistant
- Perform work on the fuel system only in well-ventilated rooms
- Relieve the fuel pressure before opening the fuel lines or fuel hoses
- Collect escaping fuel; absorb it if necessary with a suitable binding material and dispose of properly (special-category waste.)
- Pay attention to cleanliness when working on the fuel system
- Working with gasoline involves a danger of fire and explosion
- Keep away from sources of ignition
- Do not smoke
- Danger of fire due to naked flames and sparks, e.g. during welding or grinding work
- Danger of fire due to escaping fuel, e.g. on hot engine components and/or due to electrostatic charging
- Secure the vehicle, e.g. with a warning sign
- Change any clothing soaked with fuel immediately
- In case of fire, use a CO2 or dry powder fire extinguisher

WARNING:
- Danger of injury by hot and/or rotating parts
- Do not perform any work on the engine and/or exhaust system when the engine is running and/or hot.
- Danger of injury due to fan start-up. Fans can start up unexpectedly when the ignition is switched on, when control module connector B is disconnected, when the air-conditioning system is switched on or when the engine is warm. Make sure to wear safe, correctly fitting clothes and any necessary personal safety gear (hair net). Do not work in this area when the engine is running.

CAUTION:
Risk of property damage if batteries and plug connectors of the control modules are handled incorrectly.
- Never disconnect the battery terminals with the engine running.
- Never start the engine without the battery terminals properly connected.
- Never connect or disconnect the plug connections of the control modules or other electronic components with the ignition switched on.
- Please observe warnings in the Body Manual if you intend to do welding work on vehicles.