TECHNICAL SERVICE OPERATIONS

MAS002969/A (BOL 22-07)
Campaign 492
FROM Maserati TSO
TO Maserati Network

MAS002969/A – Blow-by pressure sensor faults
DATE: MAY 26 2022
This document replaces MAS002969 (BOL 22-05), please discard any paper copy of the previous bulletin

NOTE: The below in-depth diagnostic procedures are to be used along with the procedures listed in the
Workshop Manuals if a more comprehensive diagnosis is required.
The purpose of this diagnostic sheet is to provide diagnostic guidance for the DTCs related to the blow-by
pressure sensor (also named as “crankcase pressure sensor”).
MODELS: M156, M157, M161
ENGINE TYPES: F160 (V6), F154 (V8)
MODEL YEAR: MY21
SECTION: 01.90 – 2 (V6)/5 (V8) - BLOW-BY PRESSURE SENSOR
ISSUE: MIL warning light on.
CONDITIONS: No specific driving conditions. Cold ambient temperatures could have an influence.
DTC in ECU: possible DTCs in ECM:
-

P2C33 - Crankcase Pressure Sensor "B" Circuit Range/Performance
P2C34 - Crankcase Pressure Sensor "B" Circuit Low
P2C35 - Crankcase Pressure Sensor "B" Circuit High
P051B - Crankcase Pressure Sensor Circuit Range/Performance
P051C - Crankcase Pressure Sensor Circuit Low
P051D - Crankcase Pressure Sensor Circuit High

TROUBLESHOOTING: The DTCs listed above are set when the ECM reads unexpected values of the
crankcase
pressure through the dedicated sensor.
This issue can be due to one or more of the following causes:
Blow-by pressure sensor faulty
Harness damaged/poor electrical connections
Blow-by valve faulty
ECM SW is out of date
ECM corrupted

© 2022 Maserati Americas
Aftersales
www.maseratiusa.com

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

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Please refer to the images below to locate the blow-by pressure sensor on F160 (V6) and F154 (V8) engines.

Picture 1 – the blow-by pressure sensor is
located on bank 1 on F160 (V6) engines

Picture 2 - the blow-by pressure sensor is
located on bank 2 on F154 (V8) engines

© 2022 Maserati Americas
Aftersales
www.maseratiusa.com

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

2

TECHNICAL SERVICE OPERATIONS

Operational Procedure

TECHNICAL SERVICE OPERATIONS

It is required to open a BOL as “Support Request” and reporting the outcome of the checks listed in this bulletin.

Checklist:
1)

Take notes about driving and boundary conditions in which the customer has experienced this issue.
Additional information about the frequency and/or the mileage of the latest occurrence might help
with the diagnosis.

2)

Perform a preliminary scan of all the ECUs with MD EVO and save the complete report
(DTC + parameters) in pdf format. -> ►Attach to the BOL.

3)

Clear all DTCs inside the ECUs and verify the repeatability of the issue. Take notes of driving and
boundary conditions in which the issue is possibly duplicated (e.g. while driving at constant speed,
warm engine, ambient temperature -10°C, etc.)

4)

If the involved vehicle is a MY21 with P2C33 only, continue with diagnosis from Step 5.
In any other case, skip to Step 6.

5)

Check whether the ECM is already updated to one of the SW versions listed in the table below.
If not, reprogram the ECM to the indicated SW (or newer) and check if the problem is solved.
If the problem persists, proceed with the next diagnostic steps.
NOTE: If an error message (“Contact Technical Service”) appears on “ECU programming” button,
please open a BOL requesting support to solve this problem before proceeding with the next steps.

6)

MY

Models

Markets

SW Part Number

21

M15X 430HP RWD

North America

673013894

21

M161 350HP

North America

673013897

21

M15X 350HP

North America

673013895

21

M161 430HP

North America

673013896

21

M15X 430HP AWD

North America

673013893

21

M161 530HP

North America – Korea

673013162

21

M161 580HP

North America – Korea

673012373

21

M15X 580HP

North America – Korea

673012374

Disconnect the 12V battery and both connectors of the
blow-by pressure sensor and
ECM.
Refer to TechDoc wiring diagram section FE0802, check the continuity of the harness between
the blow-by pressure sensor and the ECM.
Use of the Break Out Box (BOB)and a DVOM
(with suitable back probes) is recommended. Front Probing female pins may cause damage.
- Verify the insulation of each wire is not damaged (either to the chassis ground or to each other).
- Inspect the intermediate connection of the signal line (D021) for any loose or corroded pins.
- Check the male pins on the blow-by pressure sensor and ECM for any bent/corroded pins.

7)

Re-connect the blow-by pressure sensor and ECM connectors. Re-connect the 12V battery. With the
ignition ON (KOEO), back probe and measure the voltage across pin 1 and pin 2 of the blow-by
pressure sensor connector (approximately 5V should be measured).

8)

If the above checks do not highlight any issues, remove the blow-by pressure sensor from its seat and
take two pictures of both the front and back sides of the sensors (see Picture 3 below for example).

9)

Disconnect the pipe between the blow-by valve and the RH turbocharger in correspondence to the
area indicated in Picture 4 (V6) and Picture 5 (V8) below. Take pictures of the blow-by valve
(see example shown in Picture 6 as a comparison).

10) Open a BOL as “support request” and attach and report all the information collected throughout all
above checks.

© 2022 Maserati Americas
Aftersales
www.maseratiusa.com

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

3

Picture 4 - V6 blow-by valve location

TECHNICAL SERVICE OPERATIONS

Picture 3 – blow-by pressure sensor

Picture 5 - V8 blow-by valve location

Picture 6 - blow-by valve contanmination check

© 2022 Maserati Americas
Aftersales
www.maseratiusa.com

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

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