BASIC DIAGNOSIS & TESTING INFORMATION Chevrolet El Camino V

BASIC DIAGNOSIS & TESTING INFORMATION

Diagnosis of the CCC system is done in the following order

1. Ensure that all engine systems NOT related to the CCC are fully operational. DO NOT proceed with testing unless you are sure all other problems have been fixed.
2. Enter diagnostic mode and record trouble codes flashed by CHECK ENGINE" light. Exit diagnostic mode.
3. Distinguish between "hard" or "intermittent" trouble codes.
4. If trouble codes were displayed, go to Diagnostic Circuit Check chart. Follow instructions given there.
5. If no trouble codes were recorded, go to Drive Complaint Sheet and follow instructions given there.
6. After any repairs are made, perform System Performance Check. Clear any trouble codes.

Note. The following paragraphs explain the procedures involved in performing the steps outlined above.

The ECM stores component failure information for CCC system under a related trouble code which can be recalled for diagnosis and repair. When recalled, these codes will be displayed by flashes of CHECK ENGINE" lamp. Codes are displayed starting with lowest numbered code. Only codes in which a related malfunction has occurred will be displayed.

Note. Example of trouble codes is as follows: "FLASH", "FLASH", "FLASH", pause, "FLASH", "FLASH" followed by a longer pause identifies trouble code "32". First series of flashes indicates first digit of trouble code; second series of flashes indicates second digit of trouble code.

Scheme 77

1. Turn ignition on (engine off). "CHECK ENGINE" lamp should glow. Locate Assembly Line Data Link (ALDL) connector attached to ECM wiring harness under instrument panel. Insert spade lug terminal across "TEST" terminal and "GROUND" terminal. (Scheme 77) (Scheme 77): ALDL Connector Terminal Locations
2. "CHECK ENGINE" lamp should flash code "12". Code "12" consists of "FLASH", pause, "FLASH", "FLASH" followed by a longer pause. Trouble code "12" will be repeated 2 more times, then if any trouble codes are stored in ECM memory, they will be displayed in same manner.
3. Trouble codes will be displayed from lowest to highest numbered code (3 times each) and be repeated as long as the "TEST" terminal of ALDL connector is grounded.