#### TESTING PRECAUTIONS

CAUTION
Before connecting or disconnecting control unit ECU harness connectors, make sure the ignition switch is

OFF and the negative battery cable is disconnected to avoid the possibility of damage to the control unit.

- When performing ECU input/output signal diagnosis, remove the pin terminal retainer from the 20 and 16-pin connectors to make it easier to insert tester probes into the connector.
- When connecting or disconnecting pin connectors from the ECU, take care not to bend or break any pin terminals. Check that there are no bends or breaks on ECU pin terminals before attempting any connections.
- Before replacing any ECU, perform the ECU input/output signal diagnosis to make sure the ECU is functioning properly or not.
- After performing the Electronic Control System Inspection, perform the ECCS self-diagnosis and driving test.
- When measuring supply voltage of ECU controlled components with a circuit tester, separate one tester probe from another. If the 2 tester probes accidentally make contact with each other during measurement, a short circuit will result and damage the power transistor in the ECU.

  Fig. 1: Trouble codes — 1988 200SX Models with the CA18ET engine

  Fig. 2: Trouble codes — 1988 200SX Models with the VG30E engine

  Fig. 3: Trouble codes — 1988 200SX Models with the CA20E engine

  Fig. 4: Trouble codes — 1988–92 Stanza Models

  Fig. 5: Trouble codes — 1989–92 240SX Models