Chart A5: "Check Engine" Light Inoperative Test
NOTE:
The following step numbers refer to the numbers in the accompanying flow chart(s).
- 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".
- This test checks for shorted ECM. Grounding ECM term. "G" will turn the "CHECK ENGINE" light "OFF". Normal response is lamp ON".
- 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 to 11 volts.
- This test checks for open in the wire to term. "B", normal response is approximately battery voltage.
- This test checks for an open wire to term. "E" from the CHECK ENGINE" lamp. With term. "E" grounded, lamp should normally light.
- This test checks for a grounded wire from driver term. C" to ECM term. "G". Normal response is light "ON".