On-Board Diagnostic System Description
ECM diagnosis troubles which may occur in the area including the following parts when the ignition switch is ON and the engine is running, and indicates the result by turning on or flashing malfunction indicator lamp (1).
Heated oxygen sensor (if equipped)
ECT sensor
TP sensor
IAT sensor
MAP sensor
CMP sensor
CKP sensor
Knock sensor
CPU (Central Processing Unit) of ECM
ECM and malfunction indicator lamp (1) operate as follows.
Malfunction indicator lamp (1) lights when the ignition switch is turned ON (but the engine at stop) with the diagnosis switch terminal ungrounded regardless of the condition of Engine and Emission Control system. This is only to check the malfunction indicator lamp (1) in the combination meter and its circuit.
If the above areas of Engine and Emission Control system is free from any trouble after the engine start (while engine is running), malfunction indicator lamp (1) turns OFF.
When ECM detects a trouble which has occurred in the above areas, it makes malfunction indicator lamp (1) turn ON while the engine is running to warn the driver of such occurrence of trouble and at the same time it stores the trouble area in ECM back-up memory. (The memory is kept as it is even if the trouble was only temporary and disappeared immediately. And it is not erased unless the power to ECM is shut off for specified time descried in “Time Required to Erase DTC” table under the DTC Clearance:M13A without VVT .) Also trouble are in memory can be checked either using SUZUKI scan tool (2) or reading the flashing pattern of malfunction indicator lamp using diagnosis connector (3). For further detail of the checking procedure, refer to DTC Check:M13A without VVT .
When a trouble occurs in the above areas and disappears soon while the diagnosis switch terminal is ungrounded and the engine is running, malfunction indicator lamp (1) lights and remains ON as long as the trouble exists but it turns OFF when the normal condition is restored.
Warm-Up Cycle
A warm-up cycle means sufficient vehicle operation such that the coolant temperature has risen by at least 22 °C (40 °F) from engine starting and reaches a minimum temperature of 70 °C (160 °F).
Driving Cycle
A “Driving Cycle” consists of engine startup, driving mode where a malfunction would be detected if present and engine shutoff.
Data Link Connector (DLC)
DLC (1) is in compliance with SAE J1962 in the shape of connector and pin assignment.
Serial data line (3) (K line of ISO 9141) is used for SUZUKI scan tool to communicate with ECM, TCM, Air bag SDM and ABS control module.
SUZUKI serial data line (6) is used for SUZUKI scan tool to communicate with immobilizer control module.
2. B + 4. ECM ground 5. Body ground