Mode 6
Data Output with a Scan Tool
The output of data relevant to OBD from the control modules was stipulated by law for the USA. It is described in SAE J 1979.
Data output is subdivided into different modes.
Mode 6
Output of test results of non-continuous tests.
Mode 6
The test results of components or systems which are not continuously monitored are displayed in mode 6. At the same time, limit values are provided. The test results are referred to as TID (Test Identification). The components or systems are distinguished by CIDs (Component Identification).
The following components or systems are supported:
TID $01 Catalytic converter monitoring
The catalytic converters (bank 1/bank 2) are monitored individually and for the sum of the emissions. There are two threshold values for individual monitoring:
- AHKATMN for O.K. detection and
- AHKATMX for fault detection.
For the sum of the emissions, there is the AHKATSB threshold value. A digit (ahkat) which is either 0 or 1 is used as a measurement for ageing of the catalytic converters.
0 - good
1 - bad
In the case of the individual CIDs, the limit values (maximum) and the test value of the last test are displayed.
Maximum: fault, if the test value is greater than the limit value.
The following CIDs can be displayed:
$00 Test not yet carried out
$05 Conversion bank 1
The values displayed can be multiplied by the factor 0.0039 to find the ahkat or AHKATMX values.
$06 Conversion bank 2
The values displayed can be multiplied by the factor 0.0039 to find the ahkat or AHKATMX values.
NOTE: CID $05 and $06 are displayed if the test was completed without faults. The values provide information as to how far the catalytic converter are from the limit values.
$07 Checksum error, bank 1 and bank 2
Fault codes P0420 and P0430 in memory.
The values displayed can be multiplied by the factor 0.0078 to find the ahkat1+ahkat2 or AHKATMX values.
$08 Checksum range error, bank 1
Fault code P0420 in memory.
The values displayed can be multiplied by the factor 0.0039 to find the ahkat or AHKATSB values.
$09 Checksum range error, bank 2
Fault code P0430 in memory.
The values displayed can be multiplied by the factor 0.0039 to find the ahkat or AHKATSB values.
$10 Conversion bank 1
The values displayed can be multiplied by the factor 0.0039 to find the ahkat or AHKATMX values.
$11 Conversion bank 2
The values displayed can be multiplied by the factor 0.0039 to find the ahkat or AHKATMX values.
NOTE: CID $10 and $11 are displayed if the function was carried out with the Porsche System Tester 2 in the Short test menu.
TID $03 Secondary air system
The following CIDs can be displayed:
$00 Test not yet carried out
$01 Secondary air system, bank 1
Relative secondary air mass
$04 Secondary air system, bank 2
Relative secondary air mass
NOTE:
- The relative secondary air mass is the measured secondary air mass relative to the expected nominal value (optimal value) in this operating point.
- The optimal value is detected with a faultless system. The nominal value is primarily dependant on exhaust backpressure, geographical altitude and voltage supply.
- A fault is present if the relative secondary air mass does not exceed the diagnosis threshold value.
- The values displayed can be multiplied by the factor 0.0078 to find the applied values.
TID $05 Fuel tank ventilation system
For the fuel tank ventilation system, several tests are carried consecutively but only one test value is displayed. This means that the subsequent test overwrites the preceding test value.
When all tests have been carried out, $0D (micro-leak test) is displayed.
If a different CID is displayed, the test was interrupted - either because a fault was present or, for example, the EVAP canister was excessively loaded.
The following CIDs can be displayed:
$00 Test not yet carried out
S0A Tank vent valve (leaking)
$0B Shut-off valve, EVAP canister (blocked)
$0C Major leak (pressure increase)
$0D Minor leak (leakage volumetric flow)
$11 Shut-off valve, EVAP canister (pressure reduction)
$12 Major leak (pressure sensor)
$13 Major leak (pressure sensor)
$14 Tank vent valve (constantly open)