With Scan Tool

Self Diagnostic System:

Self Diagnostic Checker:

System Selector:

When problems occur in ECU monitored input or output devices, check for the cause with Mazda Self-Diagnosis Checker (SST #49 H018 9A1) and system selector (SST #49 BO19 9AO) or equivalent aftermarket "scan" tool.

Using the SST, input and output device failures are retrieved from the ECU as malfunction code numbers. If more than one failure code is present, the lowest number malfunction code is displayed first, followed by subsequent codes in numerical order.

NOTE: The ECU continuously checks for input device malfunctions. However, it only checks for output device malfunctions during a 3 second period after the ignition switch is switched "ON" with test connector grounded.

INSPECTION PROCEDURE


1. Warm engine to operating temperature and switch ignition "OFF."

Connecting Diagnostic Tools:

2. Connect diagnostic checker and system selector to the diagnostic connector and ground (as shown in illustration).
3. Set system selector knob to the #1 position and diagnostic checker select switch to the "A" position.
4. Set system selector test switch to "SELF TEST".
5. Turn ignition switch "ON."
6. Check that digital display flashes "88" and buzzer sounds for 3 seconds after turning ignition switch "ON."
7. If "88" does not flash, inspect check connector wiring.
8. If "88" flashes and buzzer sounds continuously for more than 20 seconds, check for short circuit between ECU terminal 1F and diagnostic connector. Replace ECU if necessary and repeat previous steps.
9. Make note of any malfunction code numbers that are displayed.
10. If any codes are retrieved, repair the cause of the problem.

NOTE: Following repairs, cancel malfunction code numbers by performing after-repair procedure.


AFTER-REPAIR PROCEDURE

1. Cancel ECU malfunction code memory by disconnecting the negative battery cable and depressing the brake pedal for at least 20 seconds. Reconnect battery cable.
2. Test drive vehicle at more than 25 mph (40 kph) then stop and turn engine "OFF".
3. Connect diagnostic checker and system selector as described in inspection procedure.
4. Start engine and run at 2,000 rpm for 3 minutes, then let idle.
5. Repeat inspection procedure and note any codes.
6. If any codes recurred, recheck all work and look for other possible reasons for the code(s) (intermittent?).
7. If any new codes are retrieved, repeat step 10 of inspection procedure (above). If the same code(s) recurs, recheck repair work and look for what else might cause the code(s).