Reading and Clearing Diagnostic Trouble Codes
READING AND ERASING DIAGNOSTIC TROUBLE CODESTwo types of methods are available for reading or erasing a diagnostic trouble code; one using the Multi-Use Tester II and one using the vehicle side diagnostic functions.
1. Method using Multi-Use Tester II
Current Diagnostic Trouble Code
- Check to see that the memory clear switch 1 is connected.
- Set the starter switch to ON.
- Operate the Multi-Use Tester II to read the current diagnostic trouble code and determine the fault location.
Past Diagnostic Trouble Code
- Set the starter switch to ON.
- Disconnect the memory clear switch 1.
- Operate the Multi-Use Tester II to read the past registered diagnostic trouble codes and determine the fault location.
Erasing Diagnostic Trouble Codes
- Set the starter switch to ON.
- Operate the Multi-Use Tester II to erase all of the diagnostic trouble codes stored in the engine control unit.
2. Method Not Using Multi-Use Tester II (Method Using Diagnostic Switch and Memory Clear Switch)
Current Diagnostic Trouble Code
- Set the starter switch to ON.
- Disconnect the diagnostic switch 2.
- The diagnostic trouble code is displayed by flashes of the red warning lamp 3.
Reading Diagnostic Trouble Code
- Diagnostic trouble codes are indicated by the number of times the red warning lamp 3 flashes and their duration.
- The flashing intervals also differ between the 10s digit and the units digit.
- 10s digit: 1.2 second interval
- Units digit: 0.4 second interval
- Each diagnostic trouble code is displayed from the 1Os digit followed by the units digit. As for a code which has no 1Os digit, the units digit only is displayed.
- Each diagnostic trouble code is displayed three times in succession.
- If there is no additional codes stored, the sequence is then repeated from the beginning with each code indicated three times.
- When the diagnostic switch 2 is connected, the engine control unit will immediately stop displaying codes.
Past Diagnostic Trouble Codes
- After reading the current diagnostic trouble codes (with the diagnostic switch 2 disconnected), disconnect the memory clear switch 1. Then the warning lamp 3 will restart flashing.
- This time, the warning lamp displays the past diagnostic trouble codes. Determine the fault locations based on the indicated codes.
Erasing Diagnostic Trouble Codes
Disconnect the memory clear switch 1 and the diagnostic switch 2 then reconnect them. Then all the diagnostic trouble codes stored in the engine control unit will be cleared.
CAUTION:
- If the contents of memory are not to be cleared after display of the stored codes, set the starter switch to OFF with the memory clear switch 1 disconnected. Thereafter, connect the memory clear switch.
- When you change the combination of the injection pump and engine control unit, you must rewrite the pump data stored in the engine control unit. For this purpose, be sure to perform the diagnostic trouble code erasing procedure.
- Whenever the engine control unit has been replaced with a new one, be sure to erase the diagnostic trouble codes by disconnecting the memory clear switch 1 and diagnostic switch 2 after connecting all the connectors. Upon completing the procedure, confirm that no diagnostic trouble codes is stored.