BYD P20PS, Operator'S Manual

MAINTENANCE

OPERATOR MANUAL

37

P20PS

38

OM-P20PS2019001-EN

Schematic of Electrical System

Fault Code Table

Fault code

Fault

Fault name

Recommended inspection

02A94 NONE 

02A8

WATCHDOG  

Watchdog fault

Turn the key switch to “START”, to see whether the watchdog circuit is activated before the 

software is run. In the standby or operation state, the watchdog signal is invalid (alarm state).

Fault analysis: The watchdog hardware circuit or microcontroller output section is damaged. 

Neither of the two cases is associated with external components. Replace the controller.

02A71 EEPROM  KO

Memory is damaged

Forklift does not travel. Parameter storage becomes faulty so that forklift stops operation. 

Operate the key switch for several times. If the fault still exists, replace the logic card. If the 

fault disappears, parameters previously stored have been replaced by wrong parameters. It is 

imperative to set the parameters again.

02A17 LOGIC FAILURE #3  

Logic card fault #3

Fault with the current protection function of logic card The controller should be replaced.

02A55 LOGIC FAILURE #2 

Logic card fault #2

Fault with the phase voltage feedback hardware circuit in the logic card. Replace the 

controller.

02A54 LOGIC FAILURE #1 

Logic card fault #1

Faults caused by under-voltage or over-voltage protection. In 24V system, the controller 

detects a voltage above 45V or below 9V; In 48V system, the controller detects a voltage 

above 65V or below 11V.

Possible causes:

1.Whether there is short circuit in the circuit system, such as DC-DC, brake coil, etc., or

whether the controller input power supply is in good contact.

2.Whether the battery voltage is over low or over high.

3.Check if the power cable above the terminals such as B+, B, main contactor is tight.

4.Whether the calibration parameter of controller voltage is consistent with the actual voltage.

5.Fault with the hardware circuit protected by over-voltage on the logic card. Replace the

controller.

02A28 PUMP VMN LOW  

Oil pump VMN low

Possible cause: When the motor is turned on, the low-end voltage of MOS tube is higher than 

10% the normal battery voltage, or the phase voltage is higher than 50% the battery voltage.

Possible causes:

1.Incorrect phase connection or faulty circuit of the motor. Check the motor for incorrect

phase connection. Check the motor for current leakage to the ground. Check the motor for 

broken coil.

2.Replace the controller.

02A29 PUMP VMN HIGH

Oil pump VMN high

Possible cause: When the motor is turned on, the low-end voltage of MOS tube is higher than 

10% the normal battery voltage, or the phase voltage is higher than 50% the battery voltage.

Possible causes:

1.Incorrect phase connection or faulty circuit of the motor. Check the motor for incorrect

phase connection. Check the motor for current leakage to the ground. Check the motor for 

broken coil.

2.Replace the controller.

02A72 VMN LOW

VMN low

Possible cause: When the motor is turned on, the high-end voltage of MOS tube is less than 

66% the capacitor voltage, or when the motor is running, the high-end voltage of MOS tube is 

less than the requirement.

Possible causes:

1.Incorrect phase connection or faulty circuit of the motor. Check the motor for incorrect

phase connection. Check the motor for current leakage to the ground. Check the motor for 

broken coil.

2.Check whether the main contactor engages securely. Check the contacts for wear.

3.Replace the controller.

02A31 VMN HIGH 

VMN high

Possible cause: When the motor is turned on, the low-end voltage of MOS tube is higher than 

10% the normal battery voltage, or the phase voltage is higher than 50% the battery voltage.

Possible causes:

1.Incorrect phase connection or faulty circuit of the motor. Check the motor for incorrect

phase connection. Check the motor for current leakage to the ground. Check the motor for 

broken coil.

2.Replace the controller.

02A75

CONTACTOR 

CLOSED

Contacts of  contactor 

get stuck

Before energizing the coil of main contactor, the controller will check whether the contacts 

of main contactor get stuck. Attempt to discharge the capacitor. If the capacitor voltage is 

reduced by 20% the battery voltage, the fault could exist.

1.Check whether the contacts of the contactor get stuck. If so, replace the contactor.

02A19 LOGIC FAILURE #1

Logic fault #1

Check the battery voltage;

2.Check if the ADJUST BATTERY in the controller matches the actual battery voltage.