Contents: OBD-I systems (models produced…⇓ Reading OBD-I system trouble codes ⇓ Clearing OBD-I trouble codes ⇓ OBD-II systems (models produced…⇓ Reading OBD-II system trouble codes ⇓ Clearing OBD-II Trouble Codes ⇓
Control and measuring equipment
To test fuel injection systems and reduce exhaust emissions, it is necessary to use digital universal control and measuring instruments, as they have greater measurement accuracy and higher internal circuit resistance.
Handheld scanners are the most convenient and versatile devices for testing engine management systems on later model years.
OBD-I systems (models produced before 1995)
The electronic control unit has a built-in self-diagnostic system (On Board Diagnosis (OBD) system), which is used to search for faults in the system and turns on the check engine light on the instrument panel if faults are detected. The fault code is stored in the memory of the electronic control unit and is available for reading.
Reading OBD-I system trouble codes
To read the fault codes stored in the memory of the electronic control unit, connect the STI and GND terminals of the diagnostic connection connector.
Connect a voltmeter to the STO terminal and the vehicle ground. Turn on the ignition and count the number of deflections of the instrument needle or flashes of the engine indicator light. For example, code 34 will be displayed as 3 long flashes, a pause, 4 short flashes.
Clearing OBD-I trouble codes
To clear the fault codes, disconnect the negative battery cable and depress the brake pedal for more than 5 seconds.
OBD-I system trouble codes (1993-1995 models, except 1994 and 1995 models with a 4-cylinder engine and automatic transmission)
| Fault code | Faulty component or system |
| 02 | Crankshaft position sensor |
| 03 | Camshaft position sensor |
| 08 | Air flow sensor |
| 09 | Coolant temperature sensor |
| 11 | Air temperature sensor |
| 12 | Throttle position sensor |
| 15 | Oxygen sensor |
| 16 | Exhaust gas recirculation valve sensor |
| 17 | Oxygen sensor (check the fuel and ignition system) |
| 25 | Fuel pressure valve |
| 26 | Blow-off valve |
| 28 | Exhaust gas recirculation valve |
| 29 | Exhaust gas recirculation system ventilation valve |
| 34 | Idle air control valve |
| 67 | Cooling fan relay |
OBD-I system trouble codes (1994 and 1995 models with a 4-cylinder engine and automatic transmission)
| Fault code | Faulty component or system |
| 111 | No fault codes |
| 112, 113 | Air temperature sensor |
| 116, 117, 118 | Coolant temperature sensor |
| 121, 122, 123 | Throttle position sensor |
| 157, 158, 159 | Air flow sensor |
| 172, 173, 179, 181 | Oxygen sensor |
| 211, 212, 213 | Ignition system |
| 214, 244 | Camshaft position sensor |
| 327, 332, 337 | Exhaust gas recirculation sensor |
| 411, 412 | Idle air control valve |
| 452 | Speed sensor |
| 511, 512, 513 | Central control unit |
| 519, 521 | Power steering system switch |
| 522 | Automatic transmission sensor |
| 536 | Brake light switch |
| 538 | Dynamic test |
| 539 | Air conditioner sensor |
| 554 | Pressure regulating valve |
| 559 | Air conditioner relay |
| 563 | Relay (high speed) cooling fan |
| 564 | Relay (low speed) cooling fan |
| 565 | Blow-off valve |
| 571 | Exhaust gas recirculation ventilation valve |
| 572 | Exhaust gas recirculation system vacuum valve |
| 998 | Central control unit |
OBD-II systems (models produced since 1996)
OBD-II diagnostic connector
The connector is located under the instrument panel on the driver's side.
Models produced since 1996 feature a second-generation OBD-II self-diagnostic system. Access to this system's electronic control unit is only possible with a special scanner, which must be connected to the 16-pin diagnostic connector located under the dashboard. When a fault is detected, the electronic control unit turns on a warning light on the instrument panel and stores the fault code in its memory.
Reading OBD-II system trouble codes
To read OBD-II system trouble codes, use a special scanner that must be connected to the diagnostic connector. If you don't have a scanner, you need to contact specialists.
Clearing OBD-II Trouble Codes
To clear OBD-II system trouble codes, you need to use a special scanner.
(Information copied from the portal Mazbook)
OBD-II system trouble codes
| Fault code | Faulty component or system |
| P0100, P0102, P0103 | Air flow sensor |
| P0110, P0112, P0113 | Air temperature sensor |
| P0115, P0117, P0118 | Coolant temperature sensor |
| P0120, P0122, P0123 | Throttle position sensor |
| P0125 | It takes too long to switch to closed mode |
| P0130, P0131, P0150 | Oxygen sensor |
| P0133, P0134, P0140 | Slow response of oxygen sensor |
| P0154, P0160 | Slow response of oxygen sensor |
| P0135, P0141, P0155 | Oxygen sensor heating element |
| P0170, P0171 | Lean fuel mixture |
| P0172, P0173 | Oversaturated fuel mixture |
| P0230, P0231, P0232 | Fuel pump |
| P0300 | Random misfire |
| P0301 | Misfire in cylinder N1 |
| P0302 | Misfire in cylinder N₂ |
| P0303 | Misfire in cylinder N3 |
| P0304 | Misfire in cylinder N4 |
| P0305 | Misfire in cylinder N5 |
| P0306 | Misfire in cylinder N6 |
| P0320 | Ignition system |
| P0335 | Crankshaft position sensor |
| P0340 | Camshaft position sensor |
| P0400 | The exhaust gas recirculation system is clogged |
| P0420, P0430 | Catalytic converter |
| P0440 | Fuel vapor collection system |
| P0443 | Blow-off valve |
| P0500, P0503 | Speed sensor |
| P0505 | Idle air control valve |
| P0510 | Idle speed control switch |
| P0552, P0553 | Power steering system switch |
| P0603 | RAM error |
| P0605 | ROM error |
| P0703 | Brake light switch |
| P0704 | Clutch pedal switch |
| P0705 | Transmission sensor |
| P0710-P0760 | Gearbox control system |