Reading and Clearing Diagnostic Trouble Codes

Diagnostic Socket Location:

Testing with On-Off Ratio Tester

Various components of the CIS-E injection system are checked via the microprocessor in the CIS-E control unit. The failure codes are transmitted via the lambda measuring circuit of the diagnostic socket and are shown on the On-Off ratio tester. The fixed On-Off ratio indicates possible malfunctions. The following table lists the relationship between the fixed On-Off ratio, the cause of the failure and the respective tests to be preformed.

Test conditions
- Engine at Idle
- Coolant temperature 60-80° C
- Automatic Climate Control OFF
- Selector lever in Park
- Overvoltage protection relay fuse intact

1. Connect the on/off ratio tester to the diagnostic socket.
2. Engine at IDLE
3. If needle of On-Off ratio tester does not oscillate, refer to malfunction table.

Note: Oscillating On-Off ratio tester needle indicates no malfunctions in system.

4. Repair the indicated fault.
5. Repeat the diagnosis procedure until no more faults are present (on/off ratio tester oscillating).