Displaying Trouble Codes

After diagnostic service mode is entered, any trouble codes stored in the computer memory will be displayed. Codes will also be followed by a "C" or "H". Letter "H" stands for history and indicates that the failure was not present when last tested. Letter "C" stands for current and indicates the fault still exists. ECM codes will be displayed first. If no ECM codes are stored, a NO E CODE message is displayed.

After ECM codes have been displayed, the Body Control Module (BCM) codes will be displayed. BCM codes mainly deal with body control functions, with climate control being one of its main features. If no BCM codes are present, a NO B CODE message will be displayed. Trouble codes for both the ECM and BCM will be displayed in numerical succession of lowest to highest numbered code. Trouble code display can be bypassed at any time by depressing FAN DOWN button on ECCP or touching RTN key on CRT monitor control panel.

Fig 1: Analog Instrument Cluster & Climate Control Panel (Reatta & Riviera)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Climate Control Panel & (CRT) Monitor Control Panel (Toronado & Trofeo)

Courtesy of GENERAL MOTORS CORP.

Fig 3: Driver Information Center (DIC) (Toronado & Trofeo)

Courtesy of GENERAL MOTORS CORP.