20E1

Charge air coolant circuit : Charge air temperature is too high.

Possible cause:

- B17/8 (Charge air temperature sensor)
- M44 (charge air cooler circulation pump)
- Air in low-temperature circuit
Affected functions:

- Engine output

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Test 1: Bleed low temperature coolant circuit of charge air cooler.

Test 2: Check component M44 (charge air cooler circulation pump).

Test 3: Preconditions for test B17/8 (Charge air temperature sensor)

1. Bleed low temperature coolant circuit of charge air cooler.
Note

- WIS is not available on this system.
- It is not possible to display the requested WIS document ar2000p1145h.
- You can start WIS on another system and display the WIS document by entering the document number ar2000p1145h in the 'Contents' field.
Information

- The low temperature coolant circuit cap may only be opened when the low temperature circuit is cold (ambient temperature).To cool the low temperature circuit quickly, detach component N10/2kQ (Circulation pump relay) and link circuits 30 and 87.At the same time, actuate the electric suction fan via DAS.

2. Check component M44 (charge air cooler circulation pump).

Test 2.1: Check component M44 (charge air cooler circulation pump) by means of actuation.

Test 2.2: Test current consumption of component M44 (charge air cooler circulation pump).

Test 2.3: Check low-temperature circuit.

2.1. Check component M44 (charge air cooler circulation pump) by means of actuation.
Test sequence

- Ignition ON
- Actuate component M44 (charge air cooler circulation pump).
Actuate with key F2.

Warning!Communication with ECU required.

2.2. Test current consumption of component M44 (charge air cooler circulation pump).
Test prerequisite

- The actuation was not okay.
Test sequence

- Check fuse N10/2f116 (Fuse 116).
Question

- Is fuse N10/2f116 (Fuse 116) OK?

YES
Test prerequisite

- Component M44 (charge air cooler circulation pump) does not run.
Test sequence

- Switch off ignition.
- Detach component N10/2kQ (Circulation pump relay).
- Insert bridge for actuating component M44 (charge air cooler circulation pump).Bridge pin 3 and pin 5.(See fig.2)
- Use fuse cable for bridge.
- Measurement with multimeter
- Remove fuse N10/2f116 (Fuse 116).
- Measure direct current with multimeter between sockets (N10/2f116) 1 and (N10/2f116) 2
- Switch on ignition.
Component M44 (charge air cooler circulation pump) runs.Specified value

- Amperage 3.0...5.0 A
Question

- Is the measurement value OK?

YES
The measurement value is OK.Possible cause and remedy

- N10/2kQ (Circulation pump relay)
End of test

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

- Line from component N10/2f116 (Fuse 116) to component M44 (charge air cooler circulation pump)
- M44 (charge air cooler circulation pump)
- Check low-temperature circuit.
End of test

NO
The fuse is not o.k.Possible cause and remedy

- Test cable N10/2f116 (Fuse 116) to M44 (charge air cooler circulation pump) for Short circuit to ground.
- Visually inspect cable, repair or replace if necessary.
- M44 (charge air cooler circulation pump)
End of test

2.3. Check low-temperature circuit.
Information

- The low temperature coolant circuit cap may only be opened when the low temperature circuit is cold (ambient temperature).To cool the low temperature circuit quickly, detach component N10/2kQ (Circulation pump relay) and link circuits 30 and 87.At the same time, actuate the electric suction fan via DAS.
Continue to test with button F2

Note

- WIS is not available on this system.
- It is not possible to display the requested WIS document [ ar2000p1145h ].
- You can start WIS on another system and display the WIS document by entering the document number [ ar2000p1145h ] in the 'Contents' field.

2.3. No further information available.

3. Preconditions for test B17/8 (Charge air temperature sensor)
Status of relevant actual value:
- B17/8 (Charge air temperature sensor):Warning! Communication with ECU required.
Question

- Is the temperature of component B17/8 (Charge air temperature sensor) higher than 70° C?(158° F)

YES

Test 3.1: Check component M44 (charge air cooler circulation pump).

Test 3.2: Check component B17/8 (Charge air temperature sensor).

Test 3.3: Bleed low temperature coolant circuit of charge air cooler.

3.1. Check component M44 (charge air cooler circulation pump).

Test 3.1.1: Check component M44 (charge air cooler circulation pump) by means of actuation.

Test 3.1.2: Test current consumption of component M44 (charge air cooler circulation pump).

Test 3.1.3: Check low-temperature circuit.

3.1.1. Check component M44 (charge air cooler circulation pump) by means of actuation.
Test sequence

- Ignition ON
- Actuate component M44 (charge air cooler circulation pump).
Actuate with key F2.

Warning!Communication with ECU required.

3.1.2. Test current consumption of component M44 (charge air cooler circulation pump).
Test prerequisite

- The actuation was not okay.
Test sequence

- Check fuse N10/2f116 (Fuse 116).
Question

- Is fuse N10/2f116 (Fuse 116) OK?

YES
The measurement value is OK.Possible cause and remedy

- N10/2kQ (Circulation pump relay)
End of test

3.1.3. Check low-temperature circuit.
Information

- The low temperature coolant circuit cap may only be opened when the low temperature circuit is cold (ambient temperature).To cool the low temperature circuit quickly, detach component N10/2kQ (Circulation pump relay) and link circuits 30 and 87.At the same time, actuate the electric suction fan via DAS.
Continue to test with button F2

Note

- WIS is not available on this system.
- It is not possible to display the requested WIS document [ ar2000p1145h ].
- You can start WIS on another system and display the WIS document by entering the document number [ ar2000p1145h ] in the 'Contents' field.

3.1.3. No further information available.

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

Test 3.2.1: Check low-temperature circuit.

Test 3.2.2: Check component B17/8 (Charge air temperature sensor) using actual value.

Test 3.2.3: Check internal resistance of component B17/8 (Charge air temperature sensor).

3.2.1. Check low-temperature circuit.
Information

- The low temperature coolant circuit cap may only be opened when the low temperature circuit is cold (ambient temperature).To cool the low temperature circuit quickly, detach component N10/2kQ (Circulation pump relay) and link circuits 30 and 87.At the same time, actuate the electric suction fan via DAS.
Continue to test with button F2

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

- Air in low-temperature circuit
- Check 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

3.2.3. 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

3.3. Bleed low temperature coolant circuit of charge air cooler.
Note

- WIS is not available on this system.
- It is not possible to display the requested WIS document ar2000p1145h.
- You can start WIS on another system and display the WIS document by entering the document number ar2000p1145h in the 'Contents' field.
Information

- The low temperature coolant circuit cap may only be opened when the low temperature circuit is cold (ambient temperature).To cool the low temperature circuit quickly, detach component N10/2kQ (Circulation pump relay) and link circuits 30 and 87.At the same time, actuate the electric suction fan via DAS.

NO

Test 3.1: Check component B17/8 (Charge air temperature sensor).

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

Test 3.1.1: Check low-temperature circuit.

Test 3.1.2: Check component B17/8 (Charge air temperature sensor) using actual value.

Test 3.1.3: Check internal resistance of component B17/8 (Charge air temperature sensor).

3.1.1. Check low-temperature circuit.
Information

- The low temperature coolant circuit cap may only be opened when the low temperature circuit is cold (ambient temperature).To cool the low temperature circuit quickly, detach component N10/2kQ (Circulation pump relay) and link circuits 30 and 87.At the same time, actuate the electric suction fan via DAS.
Continue to test with button F2

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

- Air in low-temperature circuit
- Check 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

3.1.3. 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