Troubleshooting for Cummins Generator Fault Codes 331 and 332

1. Meaning

331——Cylinder 2 injector solenoid driver circuit, current below normal or open circuit.

332——Cylinder 4 injector solenoid driver circuit, current below normal or open circuit.

2. Fault Phenomenon

The diesel engine (land-based generator set drive type) may misfire or run roughly; the diesel engine (land-based generator set drive type) may lack power under heavy load.

3. Circuit Description

The injector solenoid controls fuel injection quantity and timing. The Electronic Control Module (ECM) supplies power to the solenoid by closing the high-side and low-side switches. There are two high-side switches and six low-side switches in the ECM. The injectors of cylinders 1, 2 and 3 (front row) share a single high-side switch in the ECM, connecting the injector circuit to the high-voltage power supply. Similarly, cylinders 4, 5 and 6 (rear row) also share a single high-side switch. Each injector circuit inside the ECM has a dedicated low-side switch to form a complete circuit to ground.

4. Component Location

The diesel engine (land-based generator set drive type) wiring harness connects the ECM to 3 injector circuit feed-through connectors located in the rocker arm chamber housing. The internal injector wiring harness is located under the valve cover and connects the injectors to the diesel engine (land-based generator set drive type) wiring harness at the feed-through connectors. Each feed-through connector supplies power and provides a return path for two injectors.

5. Possible Causes

① Malfunction of injectors for cylinders 1, 2, 3 causes 331 fault alarm.

② Malfunction of injectors for cylinders 4, 5, 6 causes 332 fault alarm.

③ Loose connection of the diesel engine (land-based generator set drive type) injector wiring harness or loose connection of the injector connecting wire.

④ Damaged injector solenoid (resistance value is too high or too low).

⑤ Internal damage of ECM.

6. Repair Methods

① Check if the injector wiring harness has loose connection or short circuit.

② Check if there is a short circuit caused by oil stains on the pins in the injector connecting harness.

Since 1982, Dingbo Generator has been a generator set manufacturer qualified by the "National Internal Combustion Engine Quality Supervision and Inspection Center". The product quality has passed the IS09001 quality system standard certification. And obtained the qualification certificate for self-operated import and export. Over the years, Dingbo units have been widely used in all walks of life, and have won the network access qualification of the Ministry of Information Industry, the network access qualification of the Ministry of Radio and Television, the network access qualification of CNPC, the network access qualification of China Mobile, and the manufacturing qualification of marine units. In 2016, Dingbo was awarded the Certificate of Qualified Supplier of China Nuclear Power Group. Dingbo Generator has been cooperating with Shangchai Power for many years. In 2009, it became the OEM partner of Shangchai Power in China. Dingbo generator VOLVO unit ranks the top three in the Asia-Pacific sales volume, and is the core OEM partner of Sweden Volvo in the Asia-Pacific region. If any question please feel free to visit our website https://www.dieselgeneratortech.com/ or send email to [email protected].