JCB Tier 4 Engine Start Relay High Side Voltage and Current Above Normal

Here is the instruction show you guide on how to solve JCB Tier 4 engine SPN 1321, FMI 3 and SPN 1321, FMI 6 start reply high side voltage/current above normal.

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Start Relay High Side Voltage Above Normal

Description

The start relay high side voltage is above the normal operating range.

 

Possible causes are:

The start relay wiring is defective.

The start relay is defective

 

Reaction in EEM

The FC is stored and the warning lamp is activated. The CAN message indicates active fault.

 

Solution

First save the error log and then erase it. Restart the ECU after erasing the error log. If the fault occurs again during the next driving cycle, check the following paths:

Check the start relay wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).

Check the operation with another start relay to see if the relay is defective.

 

 

Start Relay High Side Current Above Normal

Description

The start relay high side current is above the normal operating range.

 

Possible causes are:

The start relay wiring is defective.

The start relay is defective

 

Reaction in EEM

The FC is stored and the warning lamp is activated. The CAN message indicates active fault.

 

Solution

First save the error log and then erase it. Restart the ECU after erasing the error log. If the fault occurs again during the next driving cycle, check the following paths:

Check the start relay wiring, the connectors and the contact surfaces of the connector pins (possible oxidation).

Check the operation with another start relay to see if the relay is defective.

More repair case for JCB,please refer to:JCB Trouble Repair