Operation CHARM: Car repair manuals for everyone.
Home >> Mazda >> 2000 >> Millenia V6-2.5L DOHC >> Repair and Diagnosis >> Brakes and Traction Control >> Antilock Brakes / Traction Control Systems >> Service Precautions

Antilock Brakes / Traction Control Systems: Service Precautions

FOREWORD
^ Before performing the steps in Symptom Troubleshooting, perform the On-board Diagnostic Test. To check the Diagnostic Trouble Code (DTC), follow the OBD TEST steps.

PRECAUTION
When inspecting or servicing the ABS/TCS, note the following points:

Vehicles with ABS





1. The ABS warning light illuminates even when the system is normal. The ABS warning light may illuminate, even when it is normal, depending on the driving conditions and details of work performed.
2. Precautions during servicing of ABS
The ABS is composed of electrical and mechanical parts. It is necessary to categorize malfunctions as being either electrical or hydraulic when performing troubleshooting.
1) Malfunctions in electrical system
^ The ABS HU/CM has an on-board diagnostic function. With this function, the ABS warning light will come on when there is a problem in the electrical system. Also, past and present malfunctions are recorded in the ABS HU/CM. This function can find malfunctions that do not occur during periodic inspections. Turn the ignition switch on by shorting the TBS terminal and the body ground of the DLC, or by connecting the Special Service Tool (SST) (NGS tester), and approximately 5 seconds later the stored malfunctions will be displayed in the order of occurrence. To find out the causes of ABS malfunctions, use these on-board diagnostic results.
^ If a malfunction occurred in the past but is now normal, the cause is likely a temporary poor connection of the harness. The ABS HU/CM usually operates normally. Be careful when searching for the cause of malfunction.
^ After repair, it is necessary to erase the Diagnostic Trouble Code (DTC) from the ABS HU/CM memory. Also, if the ABS related parts have been replaced, verify that no DTC has been displayed after repairs.
^ After repairing the ABS wheel-speed sensor or ABS sensor rotor, or after replacing the ABS HU/CM (ABS motor or ABS motor relay or solenoid valve), the ABS warning light may not go off even when the ignition switch is turned on. In this case, drive the vehicle at a speed of more than 10km/h (6.2 mph), make sure the ABS warning light goes off, and then erase the DTC.
^ When repairing, if the ABS related connectors are disconnected and the ignition switch is turned on, the ABS HU/CM will mistakenly detect a fault and record it as a malfunction.
^ To protect the ABS HU/CM, make sure the ignition is off before connecting or disconnecting the ABS HU/CM connector.
^ To protect the terminal, use the SST (adapter harness) (49 G066 001) when connecting the tester lead to the ABS HU/CM connector.
2) Malfunctions in hydraulic system
^ Symptoms in a hydraulic system malfunction are similar to those in a conventional brake malfunction. However, it is necessary to determine if the malfunction is in an ABS component or the conventional brake system.
^ The ABS HU/CM contains delicate mechanical parts. If foreign materials get into the component, the ABS may fail to operate. Also, it will likely become extremely difficult to find the location of the malfunction in the event that the brakes operate but the ABS does not. Make sure foreign materials do not get inside when servicing the ABS (e.g. brake fluid replacement, pipe removal).

VEHICLES WITH ABS/TCS








1. The ABS warning light, Traction Control System (TCS) indicator light and/or TCS OFF light illuminate even when the system is normal. The ABS warning light, TCS indicator light and/or TCS OFF light may illuminate, even when it is normal depending on the driving conditions and details of work performed.
2. Precautions during servicing of ABS/TCS
The ABS/TCS is composed of electrical and mechanical parts. It is necessary to categorize malfunctions as being either electrical or hydraulic when performing troubleshooting.
1) Malfunctions in electrical system
^ The ABS/TCS HU/CM has an on-board diagnostic function. With this function, the ABS warning light, TCS indicator light and TCS OFF light will come on when there is a problem in the electrical system. Also, past and present malfunctions are recorded in the ABS/TCS HU/CM. This function can find malfunctions that do not occur during periodic inspections. Turn the ignition switch on by shorting the TBS terminal and the body ground of the DLC or by connecting the Special Service Tool (SST) (NGS tester), and approximately 5 seconds later the stored malfunctions will be displayed in the order of occurrence. To find out the causes of ABS/TCS malfunctions, use these on-board diagnostic results.
^ If a malfunction occurred in the past but is now normal, the cause is likely a temporary poor connection of the harness. The ABS/TCS HU/CM usually operates normally. Be careful when searching for the cause of malfunction.
^ After repair, it is necessary to erase the DTC from the ABS/TCS HU/CM memory. Also, if the ABS/TCS related parts have been replaced, verify that no Diagnostic Trouble Code (DTC) has been displayed after repairs.
^ After repairing the ABS wheel-speed sensor or ABS sensor rotor or after replacing the ABS/TCS HU/CM,(ABS motor or ABS motor relay or solenoid valve), the ABS warning light, TCS indicator light, and/or TCS OFF light may not go off even when the ignition switch is turned on. In this case, drive the vehicle at a speed of more than 10 km/h (6.2 mph), make sure the ABS warning light, TCS indicator light, and TCS OFF light go off, and then erase the DTC.
^ When repairing, if the ABS/TCS related connectors are disconnected and the ignition switch is turned on, the ABS/TCS HU/CM will mistakenly detect a fault and record it as a malfunction.
^ To protect the ABS/TCS HU/CM, make sure the ignition is off before connecting or disconnecting the ABS/TCS HU/CM.
^ To protect the terminal, use the SST (adapter harness) (49 G066 001) when connecting the tester lead to the ABS/TCS HU/CM connector.
2) Malfunctions in hydraulic system
^ Symptoms in a hydraulic system malfunction are similar to those in a conventional brake malfunction. However, it is necessary to determine if the malfunction is in an ABS component or the conventional brake system.
^ The ABS/TCS HU/CM contains delicate mechanical parts. If foreign materials get into the component, the ABS may fail to operate. Also, it will likely become extremely difficult to find the location of the malfunction in the event that the brakes operate but the ABS does not. Make sure foreign materials do not get inside when servicing the ABS (e.g. brake fluid replacement, pipe removal).
pro multis · About Operation CHARM