Diagnostic Modes

If the vehicle is to be in the Service Mode for more than a 1/2 hour with the engine Off, hook suitable trickle charger to battery to prevent the possibility of false diagnostic readings or a no start condition.
Turn ignition On, then touch Off and Warm buttons on Cathode Ray Tube's (CRT) Climate Control page simultaneously, Fig. 11. Hold buttons until a double beep is heard or a page entitled ``Service Mode'' appears.



After the Service Mode is entered, any codes stored in computer memory will be displayed as follows:

1. All ECM codes will be displayed first. Codes will be displayed for approximately two seconds with the lowest code first, followed by progressively higher codes present. All ECM codes will be prefixed with an ``E'' (EO13, EO14, etc.) before the code. If no ECM codes are stored, a ``No ECM Codes'' message will be displayed.

2. When all ECM codes or a ``No ECM Codes'' message has been displayed, all BCM codes will be displayed. BCM codes are prefixed with a ``B'' (B110, B111, etc.). If no BCM codes are stored, a ``No BCM Codes'' message will be displayed.
3. BCM codes displayed will be accompanied by a ``Current'' or ``History'' designation. ``History'' indicates the failure was not present the last time the code was tested. ``Current'' indicates the fault still exists.

4. At any time during the display of the ECM or BCM codes, if the Lo button on the IPC is touched on Toronado models, or the NO button is touched on the CRT on Riviera models, the display of codes will be bypassed. If the Bi-Lev button on the ECC panel is touched on Toronado models, or the EXIT button is touched on the CRT on Riviera models, the system will exit the service mode and go back to normal vehicle operation.

5. After all ECM and BCM codes have been displayed, or if no codes are present, a decision point is reached. ``ECM'' is displayed, and a selection from ECM, BCM or IPC data may be made. Refer to ``Service Diagnostics'' for complete operations.