P20D4

The load limit is active. (P0221)

Test 1: Compare test values of pressure sensor with one another.

Test 2: Check component B17/8 (Charge air temperature sensor).

Test 3: Test values of charge pressure control

Test 4: Check component M16/6 (Throttle valve actuator).

1. Compare test values of pressure sensor with one another.







2. Check component B17/8 (Charge air temperature sensor).

Test 2.1: Check component B17/8 (Charge air temperature sensor) using actual value.

Test 2.2: Check internal resistance of component B17/8 (Charge air temperature sensor).

2.1. Check component B17/8 (Charge air temperature sensor) using actual value.
Test sequence

- Switch on ignition.
Status of relevant actual value:
- B17/8 (Charge air temperature sensor):Warning! Communication with ECU required.
Specified value

- If the connection is unplugged at component B17/8 (Charge air temperature sensor), the value is approx. -40° C.
- Bridge pin 1 in pin 2 at the unplugged connection of component B17/8 (Charge air temperature sensor).The value is approx. 170° C.
Question

- Is the actual value o.k.?







YES
The actual value is okay.Further possible causes of fault

- Air in low-temperature circuit


NO
The actual value is not o.k.Possible cause and remedy

- Check lines from component B17/8 (Charge air temperature sensor) to component N3/10 (ME-SFI [ME] control unit).
End of test

2.2. Check internal resistance of component B17/8 (Charge air temperature sensor).
Test prerequisite

- The actual value is not o.k.
Test sequence

- Switch off ignition.
- Measure resistance with multimeter between pins (B17/8) 1 and (B17/8) 2
Specified values

- Resistor(20° C): [5763...6370]ohms
- Resistor(30° C): [3792...4191]ohms
- Resistor(40° C): [2473...2733]ohms
- Resistor(50° C): [1679...1856]ohms
- Resistor(60° C): [1165...1288]ohms
- Resistor(70° C): [822...909]ohms
- Resistor(80° C): [591...654]ohms
- Resistor(100° C): [321...355]ohms
Question

- Are the measurement values OK?







YES
The measurement values are OK.End of test

NO
The measurement values are not OK.Possible cause and remedy

- B17/8 (Charge air temperature sensor)
End of test

3. Test values of charge pressure control
Test prerequisite

- Check vehicle on roller dynamometer following continuous testing or during driving.
- Selector lever position'4'
- Transmission mode 'C'
- Gradually increase engine speed to approx. 2500 rpm in full load mode without kickdown, using the service brake to set full load and engine speed.
- Reduce engine speed to 2000 rpm.
- Increase engine speed to 2500 rpm in full load mode without kickdown and hold for 5 s.


Test values of charge pressure control







4. Check component M16/6 (Throttle valve actuator).

Test 4.1: Actuate component M16/6m1 (Actuator motor).

Test 4.2: Check component M16/6 (Throttle valve actuator) using actual value.

Test 4.3: Check internal resistance of component M16/6m1 (Actuator motor).

Test 4.4: Check internal resistance of component M16/6 (Throttle valve actuator).

Test 4.5: Test voltage supply of the potentiometers of component M16/6 (Throttle valve actuator).

4.1. Actuate component M16/6m1 (Actuator motor).
Warning!Communication with ECU required.

4.2. Check component M16/6 (Throttle valve actuator) using actual value.
Test prerequisite

- The engine is running.
Status of the relevant actual values:
- Throttle valve stop learned:Warning!
- M16/6 (Throttle valve actuator) Signal 1:Warning! Communication with ECU required.
- M16/6 (Throttle valve actuator) Signal 2:Warning! Communication with ECU required.
Specified values

- M16/6 (Throttle valve actuator)Signal 1(Idle speed): [0.30...0.90] V
- M16/6 (Throttle valve actuator)Signal 2(Idle speed): [4.00...4.60] V
- M16/6 (Throttle valve actuator)Signal 1(Full load):[0.50...1.20] V
- M16/6 (Throttle valve actuator)Signal 2(Full load):[3.90...4.60] V
Question

- Are the actual values o.k.?


YES
The actual values are okay.End of test

NO
At least one of the relevant actual values is not okay.Possible cause and remedy

- Check internal resistance of component M16/6m1 (Actuator motor).
- Check internal resistance of component M16/6 (Throttle valve actuator).
- Check power supply of component M16/6 (Throttle valve actuator).


4.3. Check internal resistance of component M16/6m1 (Actuator motor).
Test prerequisite

- The actual values are not okay.
Test sequence

- Switch off ignition.
- Disconnect coupling 1 at component N3/10 (ME-SFI [ME] control unit).
- (N3/10) 1.Measure resistance with multimeter between sockets 9 and 1.3 (N3/10)
Specified value

- Resistor[1...10]ohms
Question

- Is the measurement value OK?


YES
The measurement value is OK.End of test

NO
The measurement value is not OK.Possible cause and remedy

- Lines between N3/10 (ME-SFI [ME] control unit) and M16/6m1 (Actuator motor)
- M16/6m1 (Actuator motor)


4.4. Check internal resistance of component M16/6 (Throttle valve actuator).
Test prerequisites

- The throttle flap of component M16/6 (Throttle valve actuator) should operate freely and must not stick or rub.
- At least one of the relevant actual values is not okay.
Test sequence

- Switch off ignition.
- Remove air scoop at component M16/6 (Throttle valve actuator) (to do so, loosen charge air cooler).
- Disconnect coupling 2 at component N3/10 (ME-SFI [ME] control unit).
M16/6r1 (Throttle valve actual value potentiometer):Sliding contact 1

- [N3/10] 2.Measure resistance with multimeter between sockets 1 and 2.3 [N3/10]
- Slowly operate throttle flap by hand up to full load.
Specified values

- Idle speed[290...890]ohms
- Full load[920...1700]ohms
M16/6r1 (Throttle valve actual value potentiometer):Sliding contact 2

- [N3/10] 2.Measure resistance with multimeter between sockets 1 and 2.4 [N3/10]
- Slowly operate throttle flap by hand up to full load.
Specified values

- Idle speed[920...1700]ohms
- Full load[290...890]ohms
Question

- Are the measurement values OK?


YES
The measurement values are OK.Further possible causes of fault

- Test voltage supply of the potentiometers of component M16/6 (Throttle valve actuator).


NO
The measurement values are not OK.Possible cause and remedy

- Lines to component M16/6 (Throttle valve actuator)
- M16/6 (Throttle valve actuator)
End of test

4.5. Test voltage supply of the potentiometers of component M16/6 (Throttle valve actuator).
Test prerequisite

- At least one of the relevant actual values is not okay.
- The power supply of component N3/10 (ME-SFI [ME] control unit) is OK.
Test sequence

- Switch off ignition.
- Detach coupling at component M16/6 (Throttle valve actuator).
- Measure direct voltage with multimeter between pins (M16/6) 2 and (M16/6) 3
- Switch on ignition.
Specified value

- Voltage[4.75...5.25] V
Question

- Is the measurement value OK?







YES
The measurement value is OK.Further possible causes of fault

- M16/6 (Throttle valve actuator)
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Lines to component M16/6 (Throttle valve actuator)
- N3/10 (ME-SFI [ME] control unit)
End of test