DTC 52
DTC 52 G-sensor (Longitudinal) System (Defective Sensor)
CIRCUIT OPERATION
The AWD-ECU receives the acceleration level in the forward/reverse direction of the vehicle from the G-sensor (longitudinal).
DTC SET CONDITIONS
DTC 52 is set when the G-sensor has exceeded the specified value in a state where the ABS and brake are not operating above the vehicle speed of 10 km/h (6.2 mph).
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
^ Malfunction of the G-sensor (longitudinal)
^ Damaged harness and connector
^ Malfunction of the ABS-ECU
^ Malfunction of the AWD-ECU
DIAGNOSIS
Required Special Tool:
^ MB991958: Scan Tool (MUT-III Sub Assembly)
^ MB991824: V.C.I.
^ MB991827: USB Cable
^ MB991911: Main Harness B
STEP 1. Using scan tool MB991958, check data list item 14: G-sensor (Longitudinal) Voltage.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the LOCK (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to ON position.
3. Set scan tool MB991958 to the data reading mode.
^ Item 14: G-sensor (Longitudinal) Voltage.
^ When the vehicle is stopped (horizontal), voltage of 2.4 V - 2.6 V is displayed.
^ The voltage will fluctuate around 2.5 V while driving.
4. Turn the ignition switch to the LOCK (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent.
NO: Go to Step 2.
STEP 2. Measure the voltage at G-sensor (longitudinal) connector D-38.
1. Remove the G-sensor (longitudinal), and connect special tool harness set (MB991348) between the disconnected connectors.
2. Turn the ignition switch to the ON position.
3. Measure the voltage between terminal 2 and ground.
^ When the label on the G-sensor (Longitudinal) is horizontal, voltage of 2.4 V - 2.6 V is displayed.
^ When the label on the G-sensor (Longitudinal) is vertical, voltage of 3.3 V - 3.7 V is displayed.
4. Turn the ignition switch to the LOCK (OFF) position.
Q: Is the check result normal?
YES: Go to Step 3.
NO: Replace the G-sensor (longitudinal).
STEP 3. Measure the voltage at AWD-ECU connector C-139 by backprobing.
1. Turn the ignition switch to the ON position.
2. Measure the voltage between AWD-ECU connector C-139 terminal 23 and ground by backprobing.
^ The voltage should measure between 2.4 and 2.6 volts. (Horizontal state of vehicle)
3. Turn the ignition switch to the LOCK (OFF) position.
Q: Is the measured voltage within the specified range?
YES: Go to Step 4.
NO: Go to Step 6.
STEP 4. Check AWD-ECU connector C-139 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connector and terminals in good condition?
YES: Go to Step 5.
NO: Repair or replace the damaged components.
STEP 5. Using scan tool MB991958, check data list item 14: G-sensor (Longitudinal) Voltage.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the LOCK (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to ON position.
3. Set scan tool MB991958 to the data reading mode.
^ Item 14: G-sensor (Longitudinal) Voltage.
^ When the vehicle is stopped (horizontal), voltage of 2.4 V - 2.6 V is displayed.
^ The voltage will fluctuate around 2.5 V while driving.
4. Turn the ignition switch to the LOCK (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent.
NO: Replace the AWD-ECU.
STEP 6. Check ABS-ECU connector B-118
Q: Are the connectors and terminals in good condition?
YES: Go to Step 7.
NO: Repair or replace the damaged components.
STEP 7. Check the harness for open circuit or short circuit to ground between AWD-ECU connector C-139 terminal 23 and G-sensor (longitudinal) connector D-38 terminal 2.
Q: Is the harness wire in good condition?
YES
YES
NO: Repair or replace the harness wire.
STEP 8. Check the harness for short circuit to ground between ABS-ECU connector B-118 terminal 25 and G-sensor (longitudinal) connector D-38 terminal 2.
Q: Is the harness wire in good condition?
YES: Go to Step 5.
NO: Repair or replace the harness wire.