AfterSales Diagnostic Sheet
MAS002814

FROM: Maserati TSO
TO: Maserati Network

Air suspension system - Blown F41 fuse

5/26/2023

Section: 06.24 - 2 AIR SUSPENSION SYSTEM
Models: M161(All MY)
Problem: Difficulties changing the vehicle ride height with message “CHECK THE AIR SUSPENSION
SYSTEM” on the Instrument Panel Cluster. Vehicle may show height difference between front and rear
(front suspensions lower than the rear suspensions) and/or air suspension compressor fuse (F41 in
RDU, Rear Distribution Unit) blown.
Faults: possible DTCs stored in ASCM:
C15A1-00 (55A100) - Unable to Obtain Desired Ride Height
C15D9-00 (55D900) - Low Air Mass
C1562-98 - Ride Height Air Pump Control-Component or System Over Temperature
C2212-00 (621200) ECU - in plant mode
Inspection: Submit a BOL as “Support Request”, and attach all the requested information outlined
below:
1. Fill out Attachments A and C based on the Clean Point section, the checklist may need to be
partially or completely filled out.
2. Acquisitions recorded with PicoScope (both in psdata format and PDF format) of the currents
absorbed by the compressor, reversing valves and valve block during the execution of the active
diagnoses "Vehicle Articulation Routine" and "Actuator Test".
Clean Point: Improvements have been implemented to address the issue. Vehicles that have already
been equipped with this OEM improvement are identified as Post-Clean Point, whereas vehicles that
have not yet received this improvement are identified as Pre-Clean Point.
To distinguish between Pre-Clean Point and Post Clean Point Vehicles, please refer to the following
information:
-

Lower than: VIN349849 – Assembly Number 6077076 = Pre-Clean Point

-

Higher than: VIN349849 – Assembly Number 6077076 = Post-Clean Point

For Pre-Clean Point vehicles, perform steps 1. thru 7. of Attachment A: checklist.
For Post-Clean Point vehicles, perform steps 1. thru 9. of Attachment A: checklist.
Labor Times:
- For step 4, please refer to 06.24.001 - AIR SUSPENSION SYSTEM COMPLETE
COMPRESSOR ASSEMBLY - Air suspension system leakage test = 0.30 h.
- For step 5, if necessary, carry out the procedure CAR HEIGHT CALIBRATION - Recording and
testing with diagnostic tester = 0.35 h.
Pre-Clean Point Vehicles:
- For the remaining steps, in BOL, 0,75 h of extra-time will be granted via specific code.
Post-Clean Point Vehicles:
- For the remaining steps, in BOL, 1,5 h of extra-time will be granted via specific code.
© 2023 Maserati Americas
Aftersales
www.maseratiusa.com

MAS002814

All rights reserved. Reproduction or translation in
whole or in part is not permitted without authorization
from the publisher. Printed in USA

1

Attachment A: Checklist
Preliminary questions: in which conditions did the anomaly occur? In particular:
a. Load conditions: number of passengers and load in the luggage compartment.
Answer:

______________________________________________
b. Vehicle speed.
Answer:

______________________________________________
c. Possible additional relevant information concerning specific manoeuvres or conditions that triggered the
issue (e.g. vehicle ride height change).
Answer:

______________________________________________
d. Was the suspension stiffness setting set to hard setting (hard) or soft setting (soft) on the switch on the
Central Tunnel?

☐Soft

Hard☐

e. Was the Easy Entry/Exit functionality (Entry/Exit: easier passenger entry and exit mode) active?

☐YES

NO☐

Note: after the execution of the Active Diagnoses reported in the following, it is normal that the DTC C2212-00
(621200) - ECU In-Plant Mode is stored in the ASCM ECU. By means of the Diagnostic Tool, select the ASCM
module and carry out the ASCM > Active Diagnosis > Exit Plant Mode.
1. Is the fuse F41 in RDU (Rear Distribution Unit) blown?

☐YES

NO☐

If the answer is YES, replace it and proceed with the following steps.
If the answer is NO, proceed with the following steps.
2. With running engine, manually level the Vehicle by means of the height selector in the central tunnel.
If the Vehicle does not change its height even after the replacement of F41 fuse, verify if the DTC C221200 (621200) ECU In-Plant mode set in ASCM. If this DTC is set, enter the ASCM module with the
diagnostic tool and carry out the ASCM > Active Diagnosis > Exit Plant Mode.
Was it possible to change the Vehicle Height?

☐YES

NO☐

Did the compressor emit excessive noise while being active?

☐YES

NO☐

3. With the Diagnostic Tool, via Active Diagnosis > Ride Height, Pressure and Air Mass measures of the ASCM
module (see Figure 1), verify the Total System Air Mass and the system pressure (Air Tank (Reservoir)
Pressure) (see Figure 2).
The acceptable value of Air Tank (Reservoir) Pressure is within 5 bar and 12 bar. The acceptable value of
the Total System Air Mass is within 109 bar·liter and 159 bar·liter. The nominal value is 129 bar liter.

© 2023 Maserati Americas
Aftersales
www.maseratiusa.com

MAS002814

All rights reserved. Reproduction or translation in
whole or in part is not permitted without authorization
from the publisher. Printed in USA

2

Note: Perform the Active Diagnosis while the engine is running. It is normal for the message "Airmass Too Low"
to appear as soon as the Active Diagnosis is initiated. In such cases, it is recommended to keep the engine
running for a few minutes before clicking on the Update button. If the Active Diagnosis continues to display the
"Airmass Too Low" message with all parameters equal to zero (0), follow the steps outlined below.

Figure 1: air suspension system pressure reading with the Active Diagnosis of the ASCM ECU.

5 - 12

109 - 159

Figure 2: results of the system pressure reading Active Diagnosis.

4. Perform 06.24.001 - AIR SUSPENSION SYSTEM COMPLETE COMPRESSOR ASSEMBLY - Air
suspension system leakage test, to check if there is any leakage in the air suspension system: was there any
leakage?

☐YES

NO☐

If the answer is YES, first solve this anomaly. If the answer is NO, proceed to the next step.
5. Measure the Vehicle Height at each corner. Perform the measure as shown in Figure 3, reporting the value
in millimetres (mm) in Table 2 of Attachment C:summary table of the Vehicle Heights of each Vehicle corner.

Figure 3: measuring method of the Vehicle Height at each corner.

-

Do the Vehicle Heights of the same axle show a difference greater than 5 mm (example: front left corner
Vehicle height: 450 mm; front right corner Vehicle height: 460 mm)?

☐YES

NO☐

If YES, please proceed from step 5.1; conversely skip to step 6.
5.1. Carry out the procedure of the Workshop Manual 00.20.034 – 35 CAR HEIGHT CALIBRATION Recording and testing with diagnostic tester.
5.2. Measure Vehicle height at each corner as shown in Figure 3.
Note: fill in the column of the Table 1 of Attachment C: summary table of the Vehicle Heights of each Vehicle
corner
© 2023 Maserati Americas
Aftersales
www.maseratiusa.com

MAS002814

All rights reserved. Reproduction or translation in
whole or in part is not permitted without authorization
from the publisher. Printed in USA

3

Operations to be carried out with MDEVO
In the following, the steps to be performed using the Diagnosis tool (MD EVO), as a continuation of the previous
section, are listed.
6. Perform: Active Diagnosis > Pressure Vent Valve Actuator Test of the ASCM module = 3 times, as shown
in Figure 4. The purpose of this step is to evaluate the operation of the reversing valves (inside the
compressor), the environment valve and the pressure sensor, which is located inside the valve block.
This diagnosis forces the air circuit to be emptied between the tank and the pressure sensor via the environment
valve.
The expected result on a properly functioning car is that:
A hiss/vent noise is heard.
The height of the four corners of the vehicle should not be reduced (tolerance is 5 mm).
The diagnosis ends correctly without errors.

Figure 4: Active Diagnosis > Pressure Vent Valve Actuator Test.

6.1. Did the diagnosis complete correctly?

☐YES

NO☐

In case the active diagnosis does NOT end correctly, repeat it.
In any case, proceed from the step 6.2.

6.2. Did you hear a hiss/vent noise?

☐YES

NO☐

6.3. Measure the Vehicle heights at the four corners (as shown in Figure 3), reporting the readings in the
Table 1of Attachment C:summary table of the Vehicle Heights of each Vehicle corner.

6.4. Did the heights, on the 4 corners, change, from step 6, by more than 5 mm?

☐YES

NO☐

7. Carry out the Active Diagnosis > Deflating Component into Ambience of the ASCM module, with the following
settings:
Deflating Mode: Fixed short time deflating mode, as illustrated in Figure 5.
Deflating Component: one by one FL, FR, RL, RR, as illustrated in Figure 5.
The purpose of this step is to evaluate the operation of the environment valve and the valve of each air spring.
This diagnosis forces the emptying of the air circuit of the single air spring through the environment valve.
The expected result on a properly functioning car, is that:
A hiss/vent noise is heard.
The heights of the 4 corners of the vehicle must be reduced by a value greater than 5 mm.
By performing this Active Diagnosis individually for all four air springs, it is possible to assess their individual
functionality.

Figure 5: Active Diagnosis > Deflating Component into Ambience of the ASCM module.
© 2023 Maserati Americas
Aftersales
www.maseratiusa.com

MAS002814

All rights reserved. Reproduction or translation in
whole or in part is not permitted without authorization
from the publisher. Printed in USA

4

7.1. Was a hiss/vent noise heard?

☐YES

NO☐

7.2. Measure the Vehicle Height at each corner (as shown in Figure 3) reporting the values in the Table 1
of the Attachment C:summary table of the Vehicle Heights of each Vehicle corner.
Did the Vehicle heights for the four corners change by more than 5 mm, with respect to step 6?

☐YES

NO☐

Note: as indicated on the first page, proceed with the steps 8. And 9. For Post-Clean Point Vehicles only.
8. Carry out 10 levelling operations from Off Road 2 to Aero 2 to warm the Air Suspension System up.
•

Level the Vehicle back to normal height level.

•

Perform, twice, as better described below, the ASCM > Active Diagnosis > Vehicle Articulation
Routine.

Between the first and the second execution of the Active Diagnosis, level the Vehicle back to normal height
level. Before and after the first of the two required executions of the Active Diagnosis, it is necessary to
register, in the Table 2 of the Attachment C:summary table of the Vehicle Heights of each Vehicle corner, the
Vehicle Height of all the four corners.
To install the current clamps required for the current measurements described below, it is necessary to raise the
vehicle on a hoist. Once the installation of the current clamps is complete and the vehicle is at ground level, the
vehicle height must be recorded before beginning the Vehicle Articulation Routine.
This Active Diagnosis activates the individual single air springs by opening the single valves for a duration of 5
seconds, in the following order:
a. Front Left.
b. Front Right.
c. Rear Left.
d. Rear Right.
Simultaneously, to monitor the current absorbed by the compressor, valve block, and reversing valves during
active diagnosis executions, it is necessary to measure the current absorbed by these system components.
Please refer to Attachment B: current absorption of the compressor for detailed instructions. The purpose of this
measurement is to evaluate the performance of the ASCM ECU. For this reason, this step 8 must be repeated
twice.
First execution of the Active Diagnosis
a. Channel A: current absorbed by the compressor (B1: current absorbed by the compressor), and at the
same time
b. Channel B: current absorbed by the valve block (B2: current absorbed by the valve block).
Second execution of the Active Diagnosis:
a. Channel A: current absorbed by the compressor (B1: current absorbed by the compressor), and at the
same time
b. Channel B: current absorbed by the reversing valves inside the compressor (B3: current absorbed by
the reversing valves).
Note: it is possible to save one psdata and one PDF file of the measures with PicoScope for each one of the two
executions of the Active Diagnosis so that an overall four files are created for this step 8. If the F41 fuse blew
during this test, replace it. Did the F41 fuse blow?

☐YES

NO☐

9. Level the Vehicle back to normal height level.
Perform, the ASCM > Active Diagnosis > Actuator Test, selecting (one-by-one) 2 times:
FL (Front Left).
FR (Front Right).
After the first execution of the Active Diagnosis, reposition the vehicle to
RL (Rear Left).
its normal height level before proceeding with the second execution.
RR (Rear Right).
© 2023 Maserati Americas
Aftersales
www.maseratiusa.com

MAS002814

All rights reserved. Reproduction or translation in
whole or in part is not permitted without authorization
from the publisher. Printed in USA

5

Before and after the first of the two required executions of the Active Diagnosis, it is necessary to register, in
the Table 2 of the Attachment C:summary table of the Vehicle Heights of each Vehicle corner, the Vehicle
Height of all the four corners. The screenshot of the diagnostic tool is shown in Figure 6.