Natural gas system:
1) Yuchai Natural Gas
Diagnosis location: in front of the co-pilot/in the relay box/near ECU/above the accelerator pedal/near the instrument panel/in the fuse box near the left front wheel, etc.;
Diagnosis seat shape and configuration:
1. Square 4-pin ->AK-46;
Configuration: power cord (1), ground wire (1 or), signal wire (2);
Diagnostic line identification method:
1.K line: about 4.8V, L line: about 4.3V;
2. The difference between the two signal lines and the 5V power supply;
testing method:
1. Directly use AK-46 to diagnose, pay attention to on-board power supply;
2. Use AK-28, 15#, 13# to connect to the vehicle terminal 4.8, 4.3V respectively, pay attention to the vehicle’s power supply.
2) Shangchai Natural Gas
Diagnosis location: in front of the co-pilot/in the relay box/near ECU/above the accelerator pedal/near the instrument panel/in the fuse box near the left front wheel, etc.;
Diagnosis seat shape and configuration:
1. Square 4-pin ->AK-46;
Configuration: power cord (1), ground wire (1 or), signal wire (2);
Diagnostic line identification method:
1.K line: about 4.8V, L line: about 4.3V;
2. The difference between the two signal lines and the 5V power supply;
testing method:
1. Directly use AK-46 to diagnose, pay attention to on-board power supply;
2. Use AK-28, 15#, 13# to connect to the vehicle terminal 4.8, 4.3V respectively, pay attention to the vehicle’s power supply.
3) Xichai Natural Gas
Diagnosis location: inside the relay box, near the dashboard, etc.;
Diagnosis seat shape and configuration:
1. Flat three-pin -> AK-35 is recommended;
Configuration: ground wire (1), signal wire (2);
2. Square OBD->AK-02/28;
Configuration: power supply (1), ground wire (1), signal wire (2);
Diagnostic line identification method:
1. Special mark: One of the signal lines is between -9V ~ -5V;
2.There is a signal line of about 0.1V near -9V;
3. Pay attention to the distinction between ground wire and 0.1V signal wire.
testing method:
1. Use the dedicated connector directly;
2. Use the AK-35 universal connector to connect RS232_RD and RS232_TD to the -9V and 0.1V of the vehicle respectively, and the vehicle can take power;
4) Cummins Natural Gas
Diagnosis location: inside the relay box, near the dashboard, etc.;
Diagnosis seat shape and configuration:
1. Flat three-pin -> AK-35 is recommended;
Configuration: ground wire (1), signal wire (2);
2. Square OBD->AK-02/28;
Configuration: power supply (1), ground wire (1), signal wire (2);
Diagnostic line identification method:
1. Special mark: One of the signal lines is between -9V ~ -5V;
2.There is a signal line of about 0.1V near -9V;
3. Pay attention to the distinction between ground wire and 0.1V signal wire.
testing method:
1. Use the dedicated connector directly;
2. Use the AK-35 universal connector to connect RS232_RD and RS232_TD to the -9V and 0.1V of the vehicle respectively, and the vehicle can take power;
5) Iveco Natural Gas
Diagnosis location: inside the relay box, above the accelerator pedal, near the instrument panel, between the driver and co-driver, etc.;
Diagnosis seat shape and configuration:
1. Square standard OBD-> use AK-02/28;
Configuration: power cord (1), ground wire (1 or 2), signal wire (1, No. 7 position);
2. Round 16PIN->use AK-33;
Configuration: power cord (1), ground wire (1), signal wire (1, 8th position);
Note: Pay attention to the difference between WABCO’s ABS diagnostic interface and WABCO’s diagnostic interface on buses.
Diagnostic line identification method:
1. Check the normal power supply voltage on the vehicle;
2. The signal line on the diagnostic interface is generally about 1V lower than the normal power supply;
3.BOSCH EDC7 ECU is mostly No. 89 signal line, EDC16 ECU is mostly No. 25 signal line.
testing method:
1. Use AK-02/28 or AK-33 directly;
2. When using the AK-35 universal connector (K_LINE is K line), please use a cigarette lighter to get electricity;
3. The EDC7 signal line is No. 89, and EDC16 is mostly the No. 25 signal line. Please note that the ECU and the diagnostic instrument have the same power supply;
6) Sinotruk natural gas
Diagnosis location: near the instrument panel, inside the relay box, etc.;
Diagnosis seat shape and configuration:
1. Square standard OBD-> use AK-02/28;
Configuration: power cord (1), ground wire (1 or 2), signal wire (5);
Diagnostic line identification method:
1. Engine diagnostic line: can high, can low (6/14 2.6V, 2.4V or so);
2.Natural gas diagnostic line: can high, can low (11/12 2.6V, 2.4V or so);
3. Transmission diagnostic line: can high, can low (11/12 2.6V, 2.4V or so);
4. Body instrument (CBCU): No. 7 K line;
5. WABCO ABS: Diagnostic line No. 7, or the diagnostic interface is in the co-pilot relay box (No. 8);
testing method:
1. Use AK-33 or AK-02/28 or AK-41 directly;
2. When using the AK-35 universal connector, please use a cigarette lighter to get electricity;
7) Weichai Natural Gas
Weichai Natural Gas has two systems, please refer to ECU pictures, diagnostic interface information, etc. for judgment;
Diagnosis location: inside the relay box, near the dashboard, etc.;
Diagnosis seat shape and configuration:
1. Flat three needles;
Configuration: ground wire (1), signal wire (2);
Diagnostic line identification method:
1. Special mark: One of the signal lines is between -9V ~ -5V;
2.There is a signal line of about 0.1V near -9V;
3. Pay attention to the distinction between ground wire and 0.1V signal wire.
testing method:
1. Directly use the dedicated connector and take power from the vehicle;
2. Use the AK-35 universal connector to connect RS232_RD and RS232_TD to the -9V and 0.1V of the vehicle respectively, and the vehicle can take power;
