Without Scan Tool
ON-BOARD DIAGNOSTICSThe Powertrain Control Module (PCM) monitors its input/output signals (some signals all the time and others under specified conditions). When an irregular signal is initially monitored, the PCM decides that a malfunction has occurred and records the occurrence as a diagnostic trouble code. There are 24 diagnostic items. The diagnostic results can be read with a scan tool. A/T diagnostic trouble codes are kept in memory by direct battery feed. The codes are retained in memos even if the ignition switch is in the "LOCK" (OFF) position. A/T diagnostic trouble codes will, however, be erased when a battery terminal or the PCM connector is disconnected. In addition, the A/T diagnostic trouble code can also be erased by the scan tool MUT-II (MB991502).
NOTE: If a sensor is disconnected when the ignition switch is in the "ON" position a diagnostic trouble code Is themorized. In this case, erase the DTC using the scan tool. The 24 diagnostic items are displayed in numeric order.