Checking the Actual Values

HBA diagnosis

Checking the actual values
The specified voltage values are reference values

Test point 1
Sensor voltage, spring travel 1 (front)

- Engine off
- Vehicle on level surface
PST2 display 2 V< Us <3 V
Us = sensor voltage

The system is faulty if voltage values such as 0.4 V in the lower range or 4.5 V in the upper range are displayed. See the description for fault code 3

Test point 2
Sensor voltage, spring travel 2 (rear)

- Engine off
- Vehicle on level surface
PST2 display 2 V< Us <3 V
Us = sensor voltage

- The system is faulty if voltage values such as 0.4 V in the lower range or 4.5 V in the upper range are displayed. See the description for fault code 4

Test point 3
Terminal 15

- Engine off
- All loads switched off
PST2 display greater than 10 V

NOTE: Communication with the control module is not possible without terminal 15

Test point 4
Terminal 58

- Engine off
- Parking light off
PST2 display 0

- Engine off
- Parking light on
PST2 display 1

If 0 is displayed with the parking light on:
1. Check fuse A5
2. Pull plug off the control module
- Switch parking light on
- Measure voltage between terminal 10 and ground
Voltmeter display greater than 10 V

If the signal (terminal 58) is present at the control module, replace the control module. Check the wire if the signal (terminal 58) is not present at the control module.

NOTE: The headlights are not raised when high beam is activated if there is an open circuit at terminal 58 or if the control module is faulty.

Test point 5
ABS speed

- Engine off
- Vehicle raised
- Ignition on
- Slowly rotate the rear left wheel by hand
PST2 display greater than 1 km/h

If 0 km/h is displayed when the wheel is rotated:
1. Check fuse B9
2. Switch ignition off and pull off plug on the control module
- Switch ignition on
- Rotate the rear left wheel by hand and measure the voltage (AC range) between terminal 11 and ground
Voltmeter display greater than 1 V

If the wheel speed signal is present at the control module, replace the control module. If the wheel speed signal is not present at the control module, check the wire for open circuit or short to ground and check the ABS or PSM control module.

Test point 6
High beam

- Engine off
- Parking light off
- High beam off
PST2 display 0

- Engine off
- Parking light on
- High beam on
PST2 display 1

If 0 is displayed with the high beam on:
1. Check fuse A 1
2. Switch ignition off and pull off plug on the control module
- Switch ignition on
- Switch the high beam on and measure the voltage between plug pin 15 (high beam on signal) and ground.
Voltmeter display greater than 10 V

If the high beam signal is present at the control module, replace the control module. If the high beam signal is not present at the control module, check for an open circuit in the wire.