DTC 14
Auto-cruise Vaccum Pump Power Supply System Circuit:
Connectors:
CIRCUIT OPERATION
This circuit supplies the power to the vacuum pump. The battery positive voltage is supplied to the auto-cruise control vacuum pump by turning on the transistor at terminal number 16 of the auto-cruise control-ECU.
The conditions for turning on the transistor at terminal number 16 of the auto-cruise control-ECU are as follows.
- Ignition switch "ON"
- Auto-cruise control main switch "ON"
- Stoplight switch ON
DTC SET CONDITIONS
None of the drive signals from release valve, control valve and motor of the auto-cruise vacuum pump are input to the auto-cruise control-ECU.
TROUBLESHOOTING HINTS
The most likely causes for this code to be set are:
- Malfunction of the stoplight switch
- Malfunction of the auto-cruise vacuum pump
- Damaged connector and harness
- Malfunction of the auto-cruise control-ECU
DIAGNOSIS
STEP 1. Check the auto-cruise vacuum pump power supply voltage.
1. Disconnect auto-cruise vacuum pump connector A-01 and measure at the harness side.
2. Turn the ignition switch "ON" and auto-cruise control main switch "ON."
3. Measure the voltage between terminal 1 and ground.
- Voltage should be system voltage. If system voltage, go to Step 7.
If not system voltage, go to Step 2.
STEP 2. Check the stoplight switch.
1. Disconnect C-03 connector at the stoplight switch.
2. Connect an ohmmeter to the stoplight switch between terminals 3 and 4, and check whether there is continuity when the plunger of the stoplight switch is pushed in and an open circuit when it is released.
3. The stoplight switch is in good condition if the circuit is open when the plunger is pushed in to a depth of within 4 mm (0.2 inch) from the outer case edge surface, and if there is continuity when it is released.
If the circuit is open, replace the stoplight switch. Check that a diagnostic trouble code 14 is not output.
If there is continuity, go to Step 3.
STEP 3. Check harness connector A-01 at auto-cruise control vacuum pump for damage.
If harness connector A-01 is damaged, replace it. Refer to Harness Connector Inspection.
Then check that diagnostic trouble code 14 is not output. If harness connector A-01 is in good condition, go to Step 4.
STEP 4. Check harness connector C-03 at stoplight switch for damage.
If harness connector C-03 is damaged, replace it. Refer to Harness Connector Inspection.
Then check that diagnostic trouble code 14 is not output.
If harness connector C-03 is in good condition, go to Step 5.
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 14 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 vacuum pump connector A-01 and auto-cruise control-ECU connector C-20.
If the any harness wires between the auto-cruise control vacuum pump connector A-01 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 14 is not output. If the harness wires are in good condition, go to Step 7.
NOTE: After checking intermediate connectors C-06 and C-89, inspect the wire. If intermediate connectors C-06 and C-89 are damaged, repair or replace them. Refer to Harness Connector Inspection. Check that diagnostic trouble code 14 is not output
STEP 7. Check the auto-cruise vacuum pump
1. Disconnect the vacuum hose from the auto-cruise vacuum pump and connect a vacuum gauge to the vacuum pump.
2. Disconnect the auto-cruise vacuum pump connector.
3. Check the auto-cruise vacuum pump and valves according to the following procedure:
1. Connect the positive battery terminal to auto-cruise vacuum pump connector terminal 1, and the negative battery terminal to terminals 2, 3, and 4. The vacuum gauge should read 27 kPa (8.0 in Hg) or more.
2. The vacuum should be maintained when terminal 4 is disconnected from the negative battery terminal while terminals 1, 2, and 3 remain connected. Then the vacuum gauge should read 0 kPa (0 in Hg) when terminal 2 is disconnected from the negative battery terminal while terminals 1, and 3 remain connected.
3. The vacuum should be maintained when terminal 4 is disconnected from the negative battery terminal while terminals 1, 2, and 3 remain connected. Then the vacuum gauge should read 0 kPa (0 in Hg) when terminal 3 is disconnected from the negative battery terminal while terminals 1, and 2 remain connected.
If all of the above values are satisfied, go to Step 8.
If any of the above values are not satisfied, replace the auto-cruise vacuum pump. Then check that diagnostic trouble code 14 is not output.
STEP 8. Check harness connector A-01 at the auto-cruise control vacuum pump for damage.
If harness connector A-01 is damaged, replace it. Refer to Harness Connector Inspection.
Then check that diagnostic trouble code 14 is not output. If harness connector A-01 is in good condition, go to Step 9.
STEP 9. Check harness connector C-20 at the 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 14 is not output.
If harness connector C-20 is in good condition, go to Step 10.
STEP 10. Check the harness wires between auto-cruise control vacuum pump connector A-01 and auto-cruise control-ECU connector C-20.
If any harness wires between the auto-cruise control vacuum pump connector A-01 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 14 is not output.
If the harness wires are in good condition, replace the auto-cruise control-ECU.
Then check that diagnostic trouble code 14 is not output.
NOTE: After checking intermediate connector C-94, inspect the wire. If intermediate connector C-94 is damaged, repair or replace it. Refer to Harness Connector Inspection. Check that diagnostic trouble code 14 is not output.