DTC 15

Auto-cruise Control Switch Circuit:

CIRCUIT OPERATION
This circuit judges the signals of each switch ("OFF," "SET" "RESUME," "CANCEL" and "MAIN") of the auto-cruise control switch.
The auto-cruise control-ECU detects the stale of the auto-cruise control switch by sensing the voltages shown below.
- When all switches are OFF - 4.5 volts
- When the "SET" switch is ON - 1.5 volts
- When the "RESUME" switch is ON - 3.0 volts
- When the "CANCEL" switch is ON - 0 volt
- When the main switch is ON - 9.0 volts

DTC SET CONDITIONS
This code is output when the auto-cruise control switch "RESUME" switch, "SET" switch or "CANCEL" switch stays ON.

TROUBLESHOOTING HINTS
The most likely causes for this code to be set are:
- Malfunction of the auto-cruise control switch.
- Malfunction of the clock spring.
- Damaged connector and harness.
- Malfunction of the auto-cruise control-ECU.

DIAGNOSIS




STEP 1. Check the auto-cruise control switch.
1. Disconnect the auto-cruise control switch.
2. Measure the resistance between the terminals when each of the "SET" "RESUME," "CANCEL" and "MAIN" switches is pressed.




If the values measured correspond to those in the table below, go to Step 2.
If the values measured do not correspond to those in the table below, replace the auto-cruise control switch.

STEP 2. Check the clock spring.
Refer to Air Bag Modules and Clock Spring.
If the clock spring is in good condition, go to Step 3.
If the clock spring are damaged, replace the clock spring.
Then check that diagnostic trouble code 15 is not output.




STEP 3. Check harness connector C-82 at auto-cruise
control switch for damage.
If harness connector C-82 is damaged, replace it. Refer to Harness Connector Inspection.
Then check that diagnostic trouble code 15 is not output.
If harness connector C-82 is in good condition, go to Step 4.




STEP 4. Check the auto-cruise control switch power supply circuit.
1. Disconnect auto-cruise control switch connector C-82 and measure at the harness side.
2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 1 and ground.
- Voltage should be system voltage. If system voltage, go to Step 5.

If not system voltage, repair or replace the harness wire between the auto-cruise control switch and multi-purpose fuse number 13. Refer to Harness Connector Inspection.
Then check that diagnostic trouble code 15 is not output.




STEP 5. Check harness connector C-20 at auto-cruise
control-ECU for damage.
If harness connector C-20 is damaged, replace it. Refer to Harness Connector Inspection.
Then check that diagnostic trouble code 15 is not output.
If harness connector C-20 is in good condition, go to Step 6.







STEP 6. Check the harness wires between auto-cruise control switch connector C-82 and auto-cruise control-ECU connector C-20.
If the any harness wires between the auto-cruise control switch connector C-82 and auto-cruise control-ECU connector C-20 are damaged, repair or replace them. Refer to Harness Connector Inspection.
Then check that diagnostic trouble code 15 is not output.
If the harness wires are in good condition, replace the auto-cruise control-ECU.
Then check that diagnostic trouble code 15 is not output.