Chart A5 - "Check Engine" Light Inoperative

NOTE: The following step numbers refer to the numbers in the accompanying flow chart(s).

1. This checks for blown gauge fuse or open in "CHECK ENGINE" light circuit (including I.P. connector), printed circuit and "CHECK ENGINE" lamp. Normal response is lamp "ON".
2. This test checks for shorted ECM. Grounding ECM term. "G" will turn "CHECK ENGINE" light "OFF". Normal response is lamp "ON".
3. This test checks for grounded wire from term. "C" of lamp driver to term. "G" of ECM, an open circuit to term. "B" of lamp driver, a bad ground or faulty lamp driver. Normal reading is about 9-11 volts.
4. This test checks for open in the wire to term. "B", normal response is approximately battery voltage.
5. This checks for an open wire to term. "E" from the "CHECK ENGINE" lamp. With term. "E" grounded, lamp should normally light.
6. This test checks for a grounded wire from driver term. "C" to ECM term. "G". Normal response is light "ON".

Fig 1: Flow Chart A5, "CHECK ENGINE" Light Inoperative

Fig 2: Flow Chart A5, "CHECK ENGINE" Light Inoperative

Fig 3: Chart A5, "CHECK ENGINE" Light Inoperative - Ckt Diagram