Codes
- Contact Us -
Email: Phone: - Links -
Home
310-545-3716
Diagnostic Systems Common Generic OBDII Fault Codes (DTC) Basic OBDII Readiness Codes
1. Completed after two trips; Trip - consists of 3 main cycles (Warm-up, Driving, & Evaluation)
Porsche 993 Cycle Flag Basics
1. CAT Efficiency - monitors rear O2 sensors, must drive @ medium load & RPMs < 2500
copyright ©
2008 Systems Consulting
OBDI - On-Board Diagnostics I; a 1988 regulation requiring a MIL, engine diagnostics,
non-standard diagnostic codes, non-standard diagnostic connector & electrical interface,
and volatile fault memory
OBDII - On-Board Diagnostics II; a 1996 regulation requiring standardized diagnostic codes and
a uniform connector per SAE J2012, with emphasis on emissions system failures and
complying with J1850 or ISO 9141-2 protocol, a MIL, & a non-volatile fault memory
X1XX, X2XX - Fuel & Air Systems
X3XX - Ignition System
X4XX - Emission System
X5XX - Auxilary Functions
X6XX - Engine Control Module Functions
X7XX - Transmission Interface Functions
1XXX - OEM Proprietary
XXXZ - Same type of fault, Z - specific fault location/value
0100 - Mass Air Flow Sensor (MAFS)
0105 - Manifold Abosolute Pressure (MAP)
0110 - Intake Air Temperature (IAT)
0115 - Engine Coolant Temperature (ECT)
0120 - Throttle Position Sensor (TPS)
0130 - O2 Sensor, Bank 1 - Front Sensor
0140 - O2 Sensor, Bank 1 - Rear Sensor
0150 - O2 Sensor, Bank 2 - Front Sensor
0160 - O2 Sensor, Bank 2 - Rear Sensor
0200 - Injector Circuit
0230 - Fuel Pump Circuit
0300 - Random Cylinder Misfire
0330 - Knock Sensor (KS)
0335 - Crankshaft Position Sensor (CKP)
0340 - Camshaft Position Sensor (CMP)
0400 - Exhaust Gas Recirculation (EGR)
0410 - Secondary Air Injection (SAI)
0420 - Catalytic Converter Efficiency, Bank 1 (TWC)
0430 - Catalytic Converter Efficiency, Bank 2 (TWC)
0440 - Evaporative Emission Control System (EVAP)
0500 - Vehicle Speed Sensor (VSS)
0560 - System Battery Voltage
0605 - General Control Circuit (ECM)
0650 - Malfunction Indicator Lamp (MIL)
1. OBDII DTCs are accessed via the diagnostic link connector (DLC),
located in the passenger compartment near the steering column.
2. OBDII DTCs are not cleared by ECM/battery removal.
3. An OBDII MIL is reset by ECM/battery removal.
4. Most OBDII scanners provide a description of the generic DTCs,
in addition to the numeric code, but not for the proprietary DTCs.
5. Some OBDII DTCs do not set the MIL but are stored as pending.
6. Some OBDI/OBDII DTCs may accessed via special sequences and viewed by a flashing MIL.
Non-Continuous Tests
- Three Way Catalytic Converter (TWC) Effeciency
- Fuel Tank Ventilation (EVAP)
- Secondary Air Injection (SAI)
- Oxygen Sensors
- Oxygen Sensor Heating
Continuous Tests
- Fuel System (TRIM)
- ECM Faults (DTC)
- Cylinder Misfire
Warm-up Cycle - SAI, EVAP, (from cold start to operating temperature, 2 min. minimum)
Driving Cycle - O2 Sensors/Heating, TWC, TRIM, (2 min. idle, 5 min. drive, 2 min. idle)
Evaluation Cycle - Diagnosis of All ECM Systems
2. Completed (Set) Prior to an Emissions Test.
3. Accessed via the OBDII Connector (DLC).
4. Reset by a DTC clear, a battery disconnection, or an ECM removal.
5. Some non-continuous tests, e.g. SAI & EVAP, can be run ("Short Test") via special scanners.
6. Some early OBDII vehicles, e.g. Porsche 993 ('96), may require three trips as in #1 above
versus two trips for later vehicles ('98), e.g. updated firmware, and/or may also require a waiver
from the emissions regulatory agency. Also, some of these early vehicles may reset the readiness
codes at engine shut-down before completion of a trip requiring the starting of another new trip.
If a cycle fails, e.g. EVAP or SAI, during a subsequent trip but before completion of all necessary
trips, the required number of trips must be restarted.
2. O2 Sensor Aging - monitors O2 sensors' waveform period, must drive @ 2 load ranges,
i.e. light/medium loads
3. SAI - monitors front O2 sensors' minimum voltage, done @ idle or via Short Test
4. Tank Venting - monitors tank vacuum, done @ idle or via Short Test
5. Adaptation - monitors TRAs & FRAs, done @ idle RPM & @ 1500 < RPM < 3000
for 15 seconds @ each RPM (driving not required)
Notes: The above cycle flags when completed comprise one trip. After completion of the 1st trip,
the engine is stopped (cyclic flags reset) & restarted to begin the 2nd trip, followed by the 3rd trip
if necessary.