With Scan Tool

When problems occur in ECU monitored input or output devices, check for the cause with SST's (Mazda Special Service Tools 49 H018 9A1, 49 B019 9A0, or DT-S1000). Technician may also use equivalent aftermarket "Scan" tool. Using the SST's, input and output device failures are retrieved from ECU memory as service code numbers. If there are multiple service codes, the lowest number code is displayed first, followed by subsequent codes in numerical order.

DT-S1000 is a proprietary Mazda computerized diagnosis tool using software disks.

NOTE: The ECU continuously checks for input device malfunctions. However, it only checks for output device malfunctions in a 3 second period after the ignition switch is turned "ON" with TEN terminal of diagnosis connector grounded.

INSPECTION PROCEDURE

SST Connection:

1. Warm engine to operating temperature and turn ignition "OFF."
2. Connect System Selector (SST 49 B019 9A0) to diagnosis connector. Set system select to position "1" and test switch to "SELF TEST."
3. Connect Self-Diagnosis Checker (SST 49 H018 9A1) to System Selector. Set select switch to position "A" and turn ignition "ON."
4. Check that "88" flashes on digital display and buzzer sounds for 3 seconds after turning ignition switch "ON."
5. If "88" does not flash, inspect main relay, power supply circuit, and diagnosis connector wiring.
6. If "88" flashes and buzzer sounds continuously for more than 20 seconds, check for short circuit between ECU terminal 1F and diagnosis connector. Replace ECU if necessary and repeat previous steps.
8. Check service code numbers.

NOTE: When repairs are completed, cancel service code numbers by performing the after-repair procedure.


AFTER-REPAIR PROCEDURE (CLEARING ECU MEMORY)

1. Cancel ECU service code memory by disconnecting negative battery cable and depressing brake pedal for at least 5 seconds. Reconnect battery cable.
2. Connect SST's and verify no service codes are displayed.