Note: Refer also to the Troubleshooting section of the Introduction.
1. The ignition and fuel systems are interconnected components of the engine management system, so some of its components can also perform functions related to the fuel system.
2. When a failure is detected, the control unit records the corresponding DTC code in the memory, which can be read using a special scanner.
Note: Do not forget to clear the control unit memory after reading the fault codes and making the appropriate corrections.
3. Reading the information stored in the ECM memory in most cases allows you to determine the causes of engine failures. Analysis of the read information using the code list (see Specifications) allows you to localize the source of failure at the level of a specific element or its electrical wiring circuit.
Attention: Visual inspection of the wiring and connectors is not enough - be sure to read the information stored in the control unit memory!
4. DTCs are five-digit codes and can be identified by their alphanumeric structure. The code structure is described below using P0401 as an example (eGR adjustment, too much air mass):
1st character P - engine and transmission (Powertrain)
B - Body
C - Chassis
U - data transmission systems
2nd character 0 - standardized code (SAE/ISO)
1 - code assigned by the manufacturer
2 - standardized code (SAE/ISO)
3 - distributed area for standardized codes (SAE/ISO) and for codes assigned by the manufacturer
3rd sign 0 - fuel and air supply metering, additional equipment that reduces exhaust gas toxicity
1, 2 - dosing of fuel and air supply
3 - ignition system (petrol models)
4 - additional equipment that reduces exhaust toxicity
5 - driving speed, idle parameters and other input data
6 - on-board computer and other output data
7-9 - gearbox
A - combined drive
4th and 5th characters are the ordinal numbering of individual units or systems