Entering Diagnostic Mode (Self Diagnosis)

Fig. 76 ECCS control unit location.:

Fig. 47 Typical ECCS control unit:

1. Locate ECCS control unit, Fig. 76.
2. Ensure mode selector on control unit is turned fully counterclockwise, Fig. 47.
3. Turn ignition switch to On position and ensure inspection lamps on control unit light and remain lit. If not, check harness for battery power and grounds. If all power and ground circuits are OK, stop test, replace control unit and proceed.
4. Turn mode selector fully clockwise, Fig. 47, and ensure Codes 23, 24 (Turbo only) and 31 are displayed. If codes 23, 24 (Turbo only) and 31 are not displayed, proceed to DIAGNOSIS USING CODES to verify components and circuits. If codes 23, 24 (Turbo only) and 31 are displayed along with additional codes, note the additional codes and proceed to step 5.

NOTE: It is possible to have false codes contained in the control unit's memory. If more than two additional malfunction codes exist in the control unit's memory, or any codes at all that do not have any relation to the symptoms the vehicle exibits, it would be wise to clear the control unit memory and drive the vehicle for enough distance to recreate the code producing problem. At this point, proceed back to step 2 and continue.

5. Depress, then release accelerator pedal and ensure Codes 24 and 31 are displayed. If codes 24 (Turbo only) and 31 are not displayed, go to DIAGNOSIS USING CODES to verify components and circuits. If codes 24 (Turbo only) and 31 are displayed along with additional codes, note the additional codes and proceed to step 6.
6. For Turbo only, shift transmission from neutral through all ranges and back to neutral and ensure Code 31 is displayed. If code 31 is not displayed, go to DIAGNOSIS USING CODES to verify components and circuits. If code 31 is displayed along with additional codes, note the additional codes and proceed to step 7.
7. Start engine.
8. Ensure Codes 14 (Turbo only) and 31 are displayed. If codes 14 (Turbo only) and 31 are not displayed, go to DIAGNOSIS USING CODES to verify components and circuits. If codes 14 (Turbo only) and 31 are displayed along with additional codes, note the additional codes and proceed to step 9.
9. Drive vehicle at speed above 6 m.p.h. (Turbo only). Code 31 should be the only code left. Note additional code(s) and proceed to step 10.
10. Operate A/C momentarily and ensure Code 44 (System OK) is displayed after turning A/C off. Note any additional code(s) and proceed to step 11.
11. Turn mode selector fully counterclockwise and stop engine.
12. Perform diagnosis for codes displayed in steps 2 through 8 as described in ``DIAGNOSIS USING CODES.''