Diagnostic Sheet
FROM: After Sales - TSO
TO: Maserati Network

MAS002952 ESC - 694B00 - Recoverable failure
detected by the safety monitoring module

DATE: March 8, 2022
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 DTC 694B00 (Recoverable failure
detected by the safety monitoring module).
MODELS: M15x from MY17.
SECTION: 04.90 – 2 –ABS/ASR HYDRAULIC UNIT
ISSUE: Erroneous Parking brake warning message in the instrument cluster. In most cases, the parking brake
system works normally regardless of the error message.
CONDITIONS: No specific conditions.
DTC in ECU: Possible DTCs in the ESC module:
-

694B00 - Recoverable failure detected by the safety monitoring module
50D054 - Electronic Park Brake Module-Missing Calibration

TROUBLESHOOTING: The DTC 694B00 refers to a too low current absorption of the parking brake calipers. This
fault code is usually followed by a loss of calibration of the parking brake system, with consequent setting of
the DTC 50D054.
The issue could be due to one of the following causes:
12V battery discharged or too low;
High resistance of the wiring harness connecting the ESC module and the parking brake calipers;
Abnormal current absorption of the parking brake calipers;
ESC module corrupted.

TECHNICAL SERVICE OPERATIONS

MAS002952 (BOL 22-04)

Checklist:
1)

Perform a scan of all the ECUs with MD Evo and save the complete report (DTC + parameters) in pdf
format.

2)

Lift the vehicle and check the correct operation of the parking brake by activating it with the button on
the central tunnel. Check whether both wheels are correctly locked.

3)

Clear all DTCs in ESC and verify the issue can be reproduced. If the problem can be reproduced, take
note of the conditions in which the parking brake warning message appears in the cluster (e.g. with
ignition ON/engine idling/EPB activated/etc.).

4)

If the problem can be reproduced easily, perform the ESC active diagnosis “Maintenance open”, then
“Maintenance close”. Afterward, clear all DTCs in ESC and carry out a functional test of the parking
brake.

5)

Perform a 12V battery test with Picoscope and save the report in pdf format. Proceed with the next
diagnosis steps on the base of the result of the battery test:
a.
b.
c.

“Battery has failed”: proceed with the checks listed in section A;
“Battery is good but needs charging”: proceed with the checks listed in section B;
“Battery is good”: proceed with the checks listed in section C.

Section A: “Battery has failed”
6)

Open a BOL in order to require the authorization to replace the 12V battery (ref. MAS002623) reporting
all the data collected until this point of the diagnosis. Make sure the replacement battery is fully
charged and in good condition by performing a further battery test.

7)

Measure the sleep current absorption (battery draw). In case of abnormal values, find out the cause
of the abnormal battery draw and fix the problem before proceeding with the next steps.

8)

Clear all DTCs in ESC and verify whether the issue is solved. Should the DTC 694B00 appear again,
proceed with the diagnosis steps listed in section C.

Section B: “Battery is good but needs charging”
9)

Recharge the 12V battery (ref. MAS002623). After that, perform a further battery test with Picoscope
and make sure that the battery is fully charged.

10) Measure the sleep current absorption (battery draw). In case of abnormal values, find out the cause
of the abnormal absorption and fix the problem before proceeding with the next steps.
11) Clear all DTCs in the ESC and verify whether the issue is solved. Should the DTC 694B00 appear again,
proceed with the diagnosis steps listed in section C.

Section C: “Battery is good”
12) Referring to the wiring diagram FE0441 on Modis, verify that the wiring harness connecting the ESC and
the parking brake calipers has no abnormal resistance values (>1 Ohm). Check the insulation to
ground. Make sure there are no loose or corroded pins on the connectors of the ESC module, the
parking brake calipers or any intermediate connections.

TECHNICAL SERVICE OPERATIONS

It is required to open a BOL as a “Support Request”, reporting the outcome of the checks listed below.

TECHNICAL SERVICE OPERATIONS

13) Referring to the wiring diagram FE0501 on Modis, measure the power supply voltage to the ESC module.
Verify the integrity of the ground points and the electrical continuity of the related wiring to chassis
ground.
14) In case the checks suggested at points 12 and 13 will not highlight any issue, open a BOL as “Support
Request” providing as much information as possible in relation to the required checks.
If you have any questions, contact your Regional AfterSales Manager or the Maserati Technical Support
Helpdesk.

© 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.