Method of reading flashing codes from the "Check Engine" lamp (available on some models)

READING DIAGNOSTIC CODES

1. Turn the ignition on.
2. Fully press and release the accelerator pedal five times within five seconds.
3. If fault codes are stored in the processor memory, they will be displayed one after another by the "Check Engine" warning lamp on the instrument panel.
4. Read the flashing code.
5. The lamp stays on for 5 sec, then after 0.5 sec it lights again for 2.5 sec. After a 2.5 sec interval, the code is output. The value of each digit corresponds to the number of flashes with 0.5 sec intervals.
The higher digits of the code are output first, and the units last. The interval between code digits is 2.5 sec. After the code is output, the lamp stays on.

Note that codes (on different models) may be decimal or hexadecimal. In the second case, the number of flashes representing a code digit can range from 1 to 16. Hexadecimal digits are designated in order as follows: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F. For example, code 7F is shown by 7 short flashes and, after a pause, 15 short flashes.

Repeat the procedure to read subsequent codes.

Starting the engine automatically interrupts access to the diagnostic system.

Clearing OBD Memory

When a fault code is stored in the ECM memory, the "Check Engine" warning lamp lights up on the instrument panel. The code remains stored in the module memory.

To clear the ECM memory, connect a scan tool to the system and select the CLEARING CODES function in its menu. Then follow the instructions shown on the tool, or immediately remove the EFI fuse from its slot in the fuse box for 30 seconds.

Alternatively, the system memory can be cleared by removing the fusible link (the main fuse of the vehicle electrical system) located near the positive battery terminal (you can also simply disconnect the positive battery cable).

* Note that clearing OBD memory by disconnecting the negative battery cable erases the engine's basic settings, and engine idle stability is disturbed for a short time after the first start.

* If the vehicle stereo system has an anti-theft code, make sure you have the correct code for activating the audio system before disconnecting the battery!

* Disconnecting the battery also erases the radio's stored favorite stations. Caution: To prevent damage to the ECM, disconnect and reconnect it only with the ignition switched off!

Make sure the system memory is cleared before installing new emission control components on the engine. If the fault memory is not cleared before starting the system after replacing a faulty sensor, the PCM will store a new fault code. Clearing the memory allows the processor to reconfigure to the new parameters. During this time, for the first 50 ÷ 20 minutes after the first engine start, engine idle may be somewhat unstable.