P0300
P0300
Misfire Damaging to Catalytic Converter.
P0301
Misfire Cylinder 1, Damaging to Catalytic Converter.
P0302
Misfire Cylinder 2, Damaging to Catalytic Converter.
P0303
Misfire Cylinder 3, Damaging to Catalytic Converter.
P0304
Misfire, Cylinder 4, Damaging to Catalytic Converter.
P0305
Misfire, Cylinder 5, Damaging to Catalytic Converter.
P0306
Misfire, Cylinder 6, Damaging to Catalytic Converter.
P1313
Misfire, Cylinder 1, Emission Related.
P1314
Misfire, Cylinder 2, Emission Related.
P1315
Misfire, Cylinder 3, Emission Related.
P1316
Misfire, Cylinder 4, Emission Related.
P1317
Misfire, Cylinder 5, Emission Related.
P1318
Misfire, Cylinder 6, Emission Related.
P1319
Misfire, Emission Related.
P1585
Misfire with empty fuel tank.
Function:
To detect misfire, the decrease of engine speed is evaluated when no combustion occurs at one or more cylinders.
Faults that are emission related and faults that are damaging to the Three Way Catalytic Converter (TWC) are separate categories.
The engine speed is measured with an inductive sensor that is located above the ring gear of the flywheel.
The ring gear is divides into three segments. For the detection, the difference is calculated by the time measured between the segments. This difference is corrected by a mean value that is developed over several segments to compensate for the engine speed fluctuations caused by driving conditions. If the corrected value is above a specified value which depends on engine speed and engine load, a misfire is detected.
Diagnostic Conditions:
A cycle of 1,000 crankshaft revolutions each is evaluated (for misfire damaging to the TWC, 200 crank shaft revolutions). The misfire occurrences are compared to a threshold value. If the number of misfire is larger than the threshold value, a fault is recorded in memory.
The Malfunction Indicator Lamp (MIL) is switched on and stays on, when the misfire rate is above the threshold value for two consecutive driving cycles, when the FTP-limit values are exceeded by 1.5 times.
The MIL blinks if the misfire rate may lead to permanent damage to the TWC. The MIL goes back to consultant on when the misfire rate no longer reaches the threshold.
NOTE:
When the fuel tank is driven to empty, misfires can occur. For this reason the fuel level in the tank is also stored in memory. If the tank was empty, there was probably no fault. Erase DTC memory and road test vehicle.
DTC P1585 can be read only with a scan toot. The Porsche System Tester 2 stores the fuel tank content (full or empty) under the ambient conditions.
Short circuits to B+ or ground of the Oxygen Sensors (HO2S) ahead of the TWC cause the mixture to be too rich or too lean. This can cause misfiring. If an additional DTC for an HOS2 ahead of the TWC is stored in memory, first correct this fault and road test vehicle.
Wiring Diagram:
Diagnostic Procedure:
Test requirements: Engine mechanically OK.
1. Checking fuel pressure.
1. Undo covering cap on test connection of fuel collection pipe and remove.
2. Connect pressure gauge (special tool P 378a) with connecting line (special tool 9559) and connect to test connection.
3. Actuating fuel pump:
- with Porsche System Tester 2.
The fuel pump can be actuated with the Porsche System Tester 2 or by bridging the fuel-pump relay.
- Via fuel-pump relay without Tester.
Disconnect fuel-pump relay from the central electrical board and bridge contacts 30 and 87 (identified as 3 and 5 on the central electrical board) with a fused shop-made cable. The fuel pump must now operate or deliver fuel.
4. Nominal test values:
Stationary engine: 3.8 ± 0.2 bar.
Engine idling: 3.3 ± 0.2 bar.
NOTE: The seal or sealing ring in the brass closure cap is not exchangeable. It must therefore be used only once. Tightening torque of new brass closure cap 2.5 ± 0.5 Nm. (2.0 ± 0.5 ft. lbs.).
2. Checking quantity delivered by fuel pump.
Precondition:
Fuel filter and electrical supply in order.
1. Relieve pressure in fuel tank by opening tank cap.
2. Connect Porsche System Tester 2.
3. Raise vehicle.
4. Remove rear underside panel.
5. Disconnect fuel return line. Collect residual fuel.
6. Hold fuel line in a measuring container. Actuate fuel pump with the Porsche System Tester 2 and allow fuel to flow for 30 seconds into a measuring container.
Quantity supplied must be at least 850 cubic centimeter/30 s, i.e. after 30 seconds at least 850 cubic centimeter of fuel must be present in the measuring container.
NOTE: Always observe safety regulations.
3. Check triggering of fuel injector.
The fuel injectors can be individually suppressed with the Porsche System Tester 2 in the menu "Drive link active". The engine idle speed decreases if triggering is OK.
If no rpm decrease can be detected, check triggering as follows:
a. Voltage supply
1. Remove connector of fuel injector to be checked.
2. Connect voltmeter between injector connector, cavity 1 and ground.
3. Switch ignition on.
Specified Value: battery voltage.
If meter does not read battery voltage, check wiring according to wiring diagram for continuity or short circuit.
b. Coil resistance of fuel injectors
1. Remove connector of fuel injector to be checked.
2. With ohmmeter, measure resistance between terminals of fuel injector.
Specified Value: 11 - 13 Ohms.
c. Injection end stage (minus supply)
1. Connect special tool VAG 1315 A/1 between fuel injector and connector.
2. Connect engine tester according to manufacturer's instructions. Connect tester cable with adapter cable.
CAUTION: Tester cables must not contain ground connections.
3. Start engine: For a perfectly working injector end stage, the following display must be shown at starting rpm.
NOTE: If the engine does not start, or if the idling speed drops, replace tester cable at adapter cable.