Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode D - No DTCs And Output Won't Turn ON
Do this diagnosis if a component that is controlled by the B-CAN system does not run or come on.
- If the component does not turn off or stop, go to B-CAN System Diagnosis Test Mode C - Refer to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode C - No DTCs and Output Won t Shut OFF,
- See the B-CAN system unit input/output index for a list of input and output devices and the control units that monitor the input and control the output devices.
1. Check the fuse of the malfunctioning output device.
- If the fuse is OK, go to step 2.
- If the fuse is not OK, replace the fuse. If the fuse blows again, repair the short to ground on the fuse circuit of the malfunctioning device.
2. Check for DTCs by selecting the system MODE MENU from the HDS.
- If any DTCs are indicated, go to B-CAN System Diagnosis Test Mode A - Refer to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks .
- If any DTCs are not indicated, go to step 3.
3. Turn ON the switch that controls the malfunctioning component.
4. Select the applicable system from the system MODE MENU, then select DATA LIST, and check the input of the switch that controls the related component.
- If there is an output signal, go to step 5.
- If there is not an output signal, go to step 9.
5. Check the relay (if applicable) and ground, then check for an open or a short in the circuit for the malfunctioning component.
- If the relay and the wire harness are OK, go to step 6.
- If the relay and the wire harness are not OK, replace the relay or repair the wire circuit.
6. Do the function test for the malfunctioning component.
- If the output device pass the function test, go to step 7.
- If the output device does not pass the function test, replace the component.
7. With the malfunctioning output device connected, connect a voltmeter between the malfunctioning output device and body ground on the wire that the control unit uses to control the output device circuit.
8. Select FUNCTIONAL TESTS from the system MODE MENU, and do the forced operation test of the malfunctioning component.
- If the voltage changes (12 V to 0 V, or 0 V to 12 V), inspect the ground for the component. If OK, replace the component.
- If the voltage does not change, replace the control unit that controls the malfunctioning component.
9. Select DATA LIST from the system MODE MENU, and make sure the switch signal input for the malfunctioning system indicates a change when operated.
- If the switch input indicates ON when the switch is ON, replace the control unit that controls the malfunctioning component.
- If the switch input does not indicate ON when the switch is ON, go to step 10.
10. Check the switch and its ground (if applicable), then check for an open or a short in the wire between the switch and the control unit that monitors it.
- If the switch and the wire harness are OK, replace the control unit that monitors the switch.
- If the switch and the wire harness are not OK, replace the switch, or repair/replace the wire harness.