SP18-35E

SP18-35E
Special Bulletin
Date
Expiration
11.2018
Revision: E
Expiration date removed
Release
Page
5
1(14)
08/22/2019
P20EE (diagnostic troubleshooting code) SOLUTION - NOX CONVERSION EFFICIENCY
Prevost vehicles
B13R (9700 us/can)
DESCRIPTION
For the vehicles on which a notification for SP18-35 exists, perform the following checklist and operations. It
has been determined that these vehicles had the code (DTC) P20EE activated.
DO NOT perform this special bulletin on a specific vehicle unless a notification exists, otherwise, no
reimbursement will be awarded.
MODEL YEAR(S) AND VEHICLES INVOLVED
NOTICE TO SERVICE CENTERS
Verify vehicle eligibility by checking warranty bulletin status with SAP or via ONLINE WARRANTY SYSTEM
available on Service / Warranty tab of Prevost website.
H3-41, H3-45 coaches
Model Year : 2017 - 2019
GHG17 or OBD18 compliant vehicles
H3-45 VIP motorhomes
From 2PCH33494HC713735 up to 2PCH33492KC710467 (not incl.)
Model Year : 2017 - 2019
X3-45 coaches
GHG17 or OBD18 compliant vehicles
Model Year : 2017 - 2019
From 4RKG33491H9737417 up to 4RKG33490K9737576 (not incl.)
X3-45 coaches
Model Year : 2017 - 2019
X3-45 VIP commercial use
GHG17 or OBD18 compliant vehicles
Model Year : 2017 - 2019
From 2PCCS3495HC736180 up to 2PCCS3498KC736407 (not incl.)
X3-45 VIP motorhomes
Model Year : 2017 - 2019
VOLVO 9700
Model Year : 2017 - 2019
Writer:
EL
GHG17 or OBD18 compliant vehicles
From 3CET2V927H5184392 up to 3CET2V926K5194709 incl.

SP18-35E
Special Bulletin
Date
11.2018
MATERIAL
Expiration
Release
Page
5
2(14)
Part required
Part No.
Description
Qty
22677399
GASKET, DEF INJECTION NOZZLE
1
21376801
SEALING PLATE
1
22677399
21376801
NOTE
Material can be obtained through regular channels.
Other parts that may be required
Part No.
Description
Qty
22303390
NOx SENSOR, PRE
1
22303391
NOx SENSOR, POST
1
Writer:
EL

SP18-35E
Special Bulletin
Date
11.2018
Expiration
Release
Page
5
3(14)
DANGER
Park vehicle safely, apply parking brake, stop the engine. Prior to working on the vehicle, set the
ignition switch to the OFF position and trip the main circuit breakers equipped with a trip button. On
Commuter type vehicles, set the battery master switch (master cut-out) to the OFF position.
IMPORTANT NOTES
DO NOT perform WB18-04 or WB18-84 EMS & ACM SOFTWARE UPDATE before the
following checklist, otherwise useful diagnostic codes and monitor data could be erased.
Wb18-04 for Prevost coaches, Wb18-84 for Volvo 9700
Any troubleshooting labor of active DTCs (Diagnostic Troubleshooting Codes) other than
P20EE is considered as a separate operation of the RO (repair order) and cannot be charged
to this special bulletin.
Writer:
EL

SP18-35E
Special Bulletin
Date
Expiration
11.2018
Release
Page
5
4(14)
PART 1
Vehicle identification
H3
X3
9700



V.I.N (short) : __ ̶ __ __ __ __
OPERATIONS TO BE PERFORMED IN ADVANCE BY THE SERVICE ADVISOR
Ask the customer whether he/she noticed an abnormal consumption of oil or coolant.
Search all relevant information concerning the aftertreatment system or severe turbo failure in the history of
repairs of the vehicle and record. Attach to the repair order.
Also check if SP18-35 has already been performed on that particular coach. If this is the case, do not perform
SP18-35 once again, contact the Technical Publications for instructions. You can send a message to the
Technical Publications functional mailbox: [email protected]
NOTE/RESULTS:
Writer:
EL

SP18-35E
Special Bulletin
Date
Expiration
11.2018
Release
Page
5
5(14)
#
checklist
1
Connect PTT and check the diagnostic codes related to EMS and ACM. Take a screen capture of
the DTCs and attach to the repair order.
INITIALS
& DATE
Confirm that code P20EE is present (whether active or inactive). If P20EE is not present, do not
continue with this checklist.
Is the code P20EE present? YES 
NO
COMMENTS/RESULTS:
2
Take a screen capture of the five most recent SCR efficiency evaluations (Test screen 2589‐08‐
03‐05), attach to the repair order.
Example of SCR efficiency evaluations
Are the five most recent SCR efficiency evaluations hovering around or lower than 80%?
YES
NO
COMMENTS/RESULTS:
3
Check if there are leaks at the Charge Air Cooler (soapy water test). Check if there are leaks of
EGR, exhaust gas (between turbo and SCR converter). Note any presence of soot. Any repair is
considered as a separate operation of the RO (repair order) and cannot be charged to this special
bulletin.
Note: Try to clear exhaust clamps while keeping in mind the state of the insulating blankets
to avoid damages because the heat can make them fragile over time.
Leaks were found? YES
NO
COMMENTS/RESULTS:
Writer:
EL

SP18-35E
Special Bulletin
Date
Expiration
Release
Page
5
6(14)
11.2018
4
Remove DEF doser and perform all dosing amount tests (Test screen 2589-08-03-05) and record
the results below.
Expected values: small dosing = 49 - 60 ml
large dosing = 196 - 240 ml
Dosing amount: small________ ml
large _________ ml
Are the results from the DEF dosing amount tests normal? YES
NO
COMMENTS/RESULTS:
5
Test the concentration of DEF and record the result below. Tool: refractometer # 88890105.
Is the DEF of proper concentration?
YES 
NO
COMMENTS/RESULTS:
6
Check inside the pipe downstream of the DEF injector for any accumulation of solid (crystallized)
DEF, attach pictures of crystal accumulations if applicable. Solid DEF will be removed during
PART 2 with Sulfur Regen if applicable. Reinstall the DEF injector with two new seals.
NOTE: A small amount of crystal accumulation is normal.
Is there significant/excessive DEF crystal buildup?
YES 
NO
COMMENTS/RESULTS:
Writer:
EL

SP18-35E
Special Bulletin
Date
Expiration
11.2018
7
Release
Page
5
7(14)
Check and record the engine ECU (a.k.a. Engine Control Module ECM) software number.
To do so, check in the dashboard DID. Select DIAGNOSTICS > PART NUMBER > ENGINE ECU
Engine ECU software number: ___________________________
COMMENTS/RESULTS:
Writer:
EL

SP18-35E
Special Bulletin
Date
Expiration
Release
Page
5
8(14)
11.2018
8
Perform a NOx Conversion Test.
INSTRUCTIONS
Read all the parts of step 8 to clearly understand the purpose of the test, know which part of the
graph curves you should monitor and be aware of the possible behaviors of the conversion test.
Note: It will be necessary to start the engine from the rear of the vehicle.
-----------------------------------------------Use this test to compare the inlet and outlet NOx sensor ppm levels. Usually we monitor the last
part of the test, just before shutdown, when the engine runs at high rpm (1800 rpm). Both levels
should be close to each other at that point. See the example below (image). Take screen
captures.
IMPORTANT NOTE: If the vehicle has the engine ECU software number 23470183 (see step 7),
the test will behave differently than what is shown in the example below. In this case, refer to NOx
Conversion Test With ECU software number 23470183.
USUAL BEHAVIOR
If both NOx sensor ppm levels are close to each other during the last part, as shown in the
example above (image), then both NOx sensors are good.
If ppm levels difference exceeds 10%, then the sensor reading higher should be considered as
defective.
Writer:
EL

SP18-35E
Special Bulletin
Date
Expiration
Release
Page
5
9(14)
11.2018
𝑝𝑝𝑝𝑝𝑝𝑝 𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙 𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑 (%) =
ℎ𝑖𝑖𝑖𝑖ℎ𝑒𝑒𝑒𝑒𝑒𝑒 𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣 − 𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙 𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣
× 100
𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙 𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣𝑣
Ex.: 𝑝𝑝𝑝𝑝𝑝𝑝 𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙 𝑑𝑑𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖 (%) =
(288−279)
279
× 100 = 3.2 (%)
Are both original NOx sensors good (ppm difference ≤10%)? YES 
NO
ppm levels difference = ___________%
Replace the defective sensor 1 if applicable and then perform a new NOx sensor test once again
to make sure that the replacement sensor is good.
-----------------------------------------
NOx Conversion Test With engine ECU software number 23470183
Engine ECU software number 23470183 allows DEF dosing to continue during the last part of the
NOx conversion test (just before shutdown). This causes continued low outlet NOx sensor ppm
levels, as seen in the example below. Take screen captures.
DIFFERENT BEHAVIOR. In this example, the NOx sensors ppm levels are not close to each
other because DEF is still injected during the last part of the test. In this instance, review earlier
sections of the test to ensure that both sensors are responding to changes in the same manner.
Examples of different stages to review are shown below.
1
Change only one sensor, since both will eventually be replaced with the new SCR converter
Writer:
EL

SP18-35E
Special Bulletin
Date
11.2018
Expiration
Release
Page
5
10(14)
COMPARISON SHOULD BE DONE WHEN BOTH NOX SENSORS ARE
READING BELOW 600 ppm
The NOX sensors levels are close to each but earlier during the test (images above & below).
If both NOx sensor ppm levels are close to each other at a point during the test as shown in the
examples (image) above, then both NOx sensors are good.
If ppm levels difference is greater than 10%, then the sensor reading higher should be
considered as defective.
COMMENTS/RESULTS:
Writer:
EL

SP18-35E
Special Bulletin
Date
Expiration
Release
Page
5
11(14)
11.2018
9
If all of the five following conditions are satisfied, do not perform PART 2 of this bulletin.
Send this checklist along with screen captures to the Technical Publications to request approval
for the SCR converter replacement.
Conditions
1)
2)
3)
4)
5)
Engine is free from major component failure/performance issues
Five most recent SCR efficiency values hovering around or below 80% (step 2)
DEF dosing amount tests showed normal values (step 4)
DEF concentration within GOOD range (step 5)
Both original NOx sensors are good (step 8)
All five conditions satisfied, bulletin ended at step 9 (no need to perform sulfur regeneration nor a
road test):

Authorization for the replacement of the SCR converter. An analysis of this checklist with the
comments/results must be done in order to allow the replacement of the SCR converter. Scan and
send this checklist and all the relevant documents, photos, etc. to the Technical Publications
functional mailbox: [email protected]
Please indicate in the “subject line”: SP18-35 and the short V.I.N.
below…
as
in
the
example
COMMENTS/RESULTS:
Writer:
EL

SP18-35E
Special Bulletin
Date
Expiration
Release
Page
5
12(14)
11.2018
PART 2
#
1
checklist
INITIALS
AND
DATE
Perform one Sulfur Regeneration (Test screen 2589-08-03-02).
COMMENTS/RESULTS:
2
Do a test drive of at least 1 hour to 1 ½ hour at highway speed (45 minutes in each direction).
COMMENTS/RESULTS:
3
Connect PTT and take a screen shot of the last five (5) SCR efficiency evaluations (Test screen
2589‐08‐03‐05).
a) Make sure that the EMS has been able to carry out a new evaluation (see example
below showing the latest evaluation on top of the previous evaluations).
Note: It is very likely that a new evaluation cannot be carried out if the outside temperature
is rather cold during the road test. If this is the case, return the vehicle into service. Please
check the box below and
indicate the outside temperature.
 EMS could not carry out a new evaluation
Outside temp: _____ °
b) If SCR efficiency value on the most recent evaluation is >85% vehicle may be released
(Typical new SCR is expected to get >90% SCR efficiency). This special bulletin can then
be closed. Please, attach this filled checklist to the repair order in SAP.
c) Authorization for the replacement of the SCR converter. If post-road test SCR
efficiency value is less than 85%, an analysis of this checklist with the notes/results must
be done in order to allow the replacement of the SCR converter. Scan and send this
checklist and all the relevant documents, photos, etc. to the Technical Publications
functional mailbox: [email protected]
Please indicate in the “subject line”: SP18-35 and the short V.I.N. as in the example below…
Writer:
EL

SP18-35E
Special Bulletin
Date
Expiration
Release
Page
5
13(14)
11.2018
COMMENTS/RESULTS:
Example of SCR performance test
Before the road test
After the road test (most recent
evaluation=105%)
ADDITIONAL COMMENTSS/RESULTS:
Writer:
EL

SP18-35E
Special Bulletin
Date
Expiration
11.2018
Release
Page
5
14(14)
PARTS / WASTE DISPOSAL
Discard waste according to applicable environmental regulations (Municipal/State[Prov.]/ Federal)
ESTIMATED TIME
PART 1 only
The time required to perform PART 1 of this special bulletin is 2 hours
PART 1 & PART 2 completed
The time required to perform PART 1 & PART 2 is approximately 4 ¼ hours
OTHER
VBC Bulletin
N/A
Fail Code
04.04-1
Defect Code
9
Syst. Cond
B
Causal Part
21970125
Access all our Service Bulletins on
http://techpub.prevostcar.com/en/
or scan the QR-Code with your smart phone.
Prevost engages in a continuous program of testing and evaluating to provide the best possible product. Prevost, however, is not committed
to, or liable for updating existing products.
Writer:
EL