Turn Signals: Testing and Inspection

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER TO AIR BAGS AND SEAT BELTS/AIR BAGS BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. Turn the ignition switch to the On position. Activate the turn signal switch by moving the left multi-function switch control stalk up (right turn) and/or down (left turn). Observe the turn signal indicator lamp(s) in the instrument cluster. If the flash rate is very high, check for a turn signal bulb that is not lit or is very dimly lit. Repair the circuits to that lamp or replace the faulty bulb, as required. Test the operation of the turn signal system again. If the turn signal indicator(s) fail to light, go to Step 2.
2. Turn the ignition switch to the Off position. Check the fused B(+) fuse in the junction block. If OK, go to Step 3. If not OK, repair the shorted circuit or component as required and replace the faulty fuse(s).
3. Check for battery voltage at the fused B(+) fuse in the junction block. If OK, go to Step 4. If not OK, repair the open fused B(+) circuit to the Power Distribution Center (PDC) fuse as required.
4. Check the fused ignition switch output (run) fuse in the junction block. If OK, go to Step 5. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
5. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output (run) fuse in the junction block. If OK, go to Step 6. If not OK, repair the open fused ignition switch (run) circuit to the ignition switch as required.
6. Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Remove the combination flasher from the junction block and replace it with a known good unit. Connect the battery negative cable. Test the operation of the turn signal and hazard warning systems. If OK, discard the faulty combination flasher. If not OK, remove the test flasher and go to Step 7.
7. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output (run) circuit cavity for the combination flasher in the junction block. If OK, go to Step 8. If not OK, repair the open fused ignition switch output (run) circuit to the junction block fuse as required.
8. Turn the ignition switch to the Off position. Check for battery voltage at the fused B(+) circuit cavity for the combination flasher in the junction block. If OK, go to Step 9. If not OK, repair the open fused B(+) circuit to the junction block fuse as required.
9. Disconnect and isolate the battery negative cable. Disconnect the instrument panel wire harness connector from the turn signal and hazard warning (left multi-function) switch connector receptacle. Check for continuity between the ground circuit cavity of the instrument panel wire harness connector for the left multi-function switch and a good ground. There should be continuity. If OK, go to Step 10. If not OK, repair the open ground circuit to ground as required.
10. Check for continuity between the hazard switch sense circuit cavity of the instrument panel wire harness connector for the left multi-function switch and a good ground. There should be no continuity. If OK, go to Step 11. If not OK, repair the shorted hazard switch sense circuit as required.
11. Check for continuity between the hazard switch sense circuit cavities of the junction block for the combination flasher and the instrument panel wire harness connector for the left multi-function switch. There should be continuity. If OK, go to Step 12. If not OK, repair the open hazard switch sense circuit as required.
12. Check for continuity between the left turn switch sense circuit cavity of the instrument panel wire harness connector for the left multi-function switch and a good ground. There should be no continuity If OK, go to Step 13. If not OK, repair the shorted left turn switch sense circuit as required.
13. Check for continuity between the left turn switch sense circuit cavities of the junction block for the combination flasher and the instrument panel wire harness connector for the left multi-function switch. There should be continuity. If OK, go to Step 14. If not OK, repair the open left turn switch sense circuit as required.
14. Check for continuity between the right turn switch sense circuit cavity of the instrument panel wire harness connector for the left multi-function switch and a good ground. There should be no continuity. If OK, go to Step 15. If not OK, repair the shorted right turn switch sense circuit as required.
15. Check for continuity between the right turn switch sense circuit cavities of the junction block for the combination flasher and the instrument panel wire harness connector for the left multi-function switch. There should be continuity. If OK, refer to Turn Signal and Hazard Warning Switch in the Diagnosis and Testing to test the left multi-function switch. If not OK, repair the open right turn switch sense circuit as required.