DTC 82

DTC 81, 82, 83: Steering Angular Velocity Sensor System









CIRCUIT OPERATION
The steering angular velocity sensor monitors the steering angle and outputs the ST-1, ST-2 and ST-N signals. The ABS-ECU calculates the steering angle by reading the signals from the steering angular velocity sensor.

ABS DTC SET CONDITIONS
DTC 81 (ST-1), DTC 82 (ST-2) and DTC 83 (ST-N) are output if there is a fault in the steering angular velocity sensor, an open circuit or short circuit in the signal lines, or the internal circuit in the hydraulic unit and ABS-ECU is defective.

TROUBLESHOOTING HINTS
The most likely causes for these DTCs to set are:
^ Malfunction of the steering angular velocity sensor
^ Damaged wiring harness and connector
^ Malfunction of the brake modulator hydraulic unit (integrated with ABS-ECU)

DIAGNOSIS
Required Special Tools:
^ MB991223: Harness Set
^ MB991529: Diagnostic Trouble Code Check Harness
^ MB991958: Scan Tool (MUT-III Sub Assembly)
^ MB991824: Vehicle Communication Interface (V.C.I.)
^ MB991827: MUT-III USB Cable
^ MB991911: MUT-III Main Harness B

STEP 1. Using scan tool MB991958, check data list.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the LOOK (OFF) position before connecting or disconnecting scan tool MB991958.





1. Connect scan tool MB991958 as shown in the illustration.
2. Start the engine.
3. Set scan tool MB991958 to data reading mode for following items.
^ Item 74: Steering angular velocity (ST-N)
^ Item 75: Steering angular velocity (ST-1)
^ Item 76: Steering angular velocity (ST-2)





4. Confirm the indicated ON/OFF state as follows:
Q: Is the steering angular velocity sensor input normal?
YES: This malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope With Intermittent Malfunction.
NO: Go to Step 2.

STEP 2. Check the power supply circuit. Measure the voltage at steering angular velocity sensor connector C-230.





1. Disconnect connector C-230, and check at the harness side.
2. Turn the ignition switch to the ON position.
3. Measure the voltage between terminal 2 and ground. It should measure approximately 12 volts (battery positive voltage).
Q: Is battery positive voltage (approximately 12 volts) present?
YES: Go to Step 3.
NO: Go to Step 4.

STEP 3. Check the ground circuit. Measure the resistance at steering angular velocity sensor connector C-230.





1. Disconnect connector C-230, and check at the harness side.
2. Measure the resistance between terminal 3 and ground. It should measure less than 2 ohms.
Q: Is the resistance 2 ohms or less?
YES: Go to Step 8.
NO: Go to Step 6.

STEP 4. Check the following connectors.





^ Steering angular velocity sensor connector C-230





^ Junction block connectors C-210, C-211





^ Joint connector C-101
Check the connectors for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?
YES: Go to Step 5.
NO: Repair it and then go to Step 11.

STEP 5. Check the following harness wire.








The wire between steering angular velocity sensor connector C-230 (terminal 2) and junction block connector C-211 (terminal 2)
Q: Is the harness wire damaged?
YES: Repair or replace it and then go to Step 11.
NO: Go to Step 11.

STEP 6. Check the following connectors.





^ Steering angular velocity sensor connector C-230





^ Joint connector C-06
Check the connectors for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?
YES: Go to Step 7.
NO: Repair it and then go to Step 11.








STEP 7. Check the following harness wires.





The wire between steering angular velocity sensor connector C-230 (terminal 3) and ground (No.3, No.14)
Q: Is any harness wire damaged?
YES: Repair or replace it and then go to Step 11.
NO: Go to Step 11.

STEP 8. Check steering angular velocity sensor output voltage.





1. Connect steering angular velocity sensor connector C-230.
2. Turn the ignition switch to the ON position.





3. Measure the voltage, by backprobing, between terminal 1 and ground, terminal 4 and ground, and terminal 5 and ground. The voltage should measure as indicated in the figure.
Q: Is the steering angular velocity sensor output voltage normal?
YES: Go to Step 9.
NO: Replace the steering angular velocity sensor. Then go to Step 11.

STEP 9. Check the following connectors.





^ Steering angular velocity sensor connector C-230





^ Intermediate connector C-122





^ ABS-ECU connector B-118
Check the connectors for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?
YES: Go to Step 10.
NO: Repair it and then go to Step 11.

STEP 10. Check the following harness wires.








^ If DTC 81 (ST-1) is set: The wire between steering angular velocity sensor connector C-230 (terminal 5) and ABS-ECU connector B-118 (terminal 26)
^ If DTC 82 (ST-2) is set: The wire between steering angular velocity sensor connector C-230 (terminal 4) and ABS-ECU connector B-118 (terminal 17)
^ If DTC 83 (ST-N) is set: The wire between steering angular velocity sensor connector C-230 (terminal 1) and ABS-ECU connector B-118 (terminal 4)
Q: Is any harness wire damaged?
YES: Repair or replace it and then go to Step 11.
NO: Replace the brake modulator hydraulic unit (integrated with ABS-ECU). Then go to Step 11.

STEP 11. Recheck for diagnostic trouble code.





Check again if the DTC is set.
1. Turn the ignition switch to the ON position.
2. Erase the DTC.
3. Turn the ignition switch to the LOCK (OFF) position.
4. Turn the ignition switch to the ON position.
5. Check if the DTC is set.
6. Turn the ignition switch to the LOCK (OFF) position.
Q: Does DTC 81, 82 and/or 83 reset?
YES: Return to Step 1.
NO: The procedure is complete.