Some codes do have an alpha character, MB–or at least they do on some late-model Fords.
The problem has to do with the evaporative emissions system.
Here is the text of the TSB that relates to this situation:
11-11-28
MIL LAMP ON WITH DTCS P144A, P2196, P2198, P1450, P0455, P0456, AND/OR P0457 BUILT ON OR BEFORE 3/4/2011
Publication Date: November 18, 2011
FORD:
2010-2011 Fusion
2009-2011 Escape
MERCURY:
2010-2011 Milan
2009-2011 Mariner
This article supersedes TSB 11-3-22 to update the Title, Issue Statement, and Service Procedure. ISSUE:
Some 2009-2011 Escape, Mariner, 2010-2011 Fusion and Milan vehicles equipped with a 2.5L DOHC or 3.0L engine built on or before 3/4/2011 may exhibit a leaking/stuck under hood evaporative emission purge valve. This fault will turn on the malfunction indicator lamp (MIL) and set diagnostic trouble codes (DTC) P144A, P2196, P2198, P1450, P0455, P0456, and/or P0457.
ACTION:
Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE
1.Are any of the following DTCs P144A, P2196, P2198, P1450, P0455, P0456, and/or P0457 present?
1.No - Do not continue with this article.
2.Yes - Proceed to Step 2.
2.Remove the evaporative emission canister. Refer to Workshop Manual (WSM), Section 303-13. Inspect canister for liquid fuel by turning the canister over and watching for signs of liquid fuel exiting the canister. Are there any signs of liquid fuel present?
1.No - Proceed to Step 3.
2.Yes - Replace the evaporative emission canister. Refer to WSM, Section 303-13. Proceed to Step 3.
3.Are P0455, P0456, and/or P0457 the only DTCs present?
1.No - Refer to the WSM, Section 303-13 to locate the leak. Repair as needed.
2.Yes - Proceed to Step 4.
4.Perform IDS leak test, Refer to the Powertrain Control/Emission Diagnosis (PC/ED) pin point text HX. Did the leak test pass?
1.No - Refer to WSM, Section 303-13. to locate the leak. Repair as needed.
2.Yes - Replace the under hood evaporative emission canister purge valve. Refer to WSM, Section 303-13 and proceed to Step 5.
5.Clear stored DTCs.
PART NUMBERPART NAME9U5Z-9C915-HCanister Purge Valve9R3Z-9C985-BCanister (Escape/Mariner)9E5Z-9D653-CCanister (Fusion/Milan)
WARRANTY STATUS:
Eligible Under Provisions Of New Vehicle Limited Warranty Coverage And Emissions Warranty Coverage
IMPORTANT: Warranty/ESP coverage limits/policies are not altered by a TSB. Warranty/ESP coverage limits are determined by the identified causal part and verified using the OASIS part coverage tool.
OPERATIONDESCRIPTIONTIME111128A2010-2011 Fusion And Milan: Check DTCs, Remove And Inspect The Evaporative Emission Canister, Replace If Necessary Includes Time To Perform The Evaporative Emission System Leak Test0.9 Hr.111128A2009-2011 Escape And Mariner: Check DTCs, Remove And Inspect The Evaporative Emission Canister, Replace If Necessary, Includes Time To Perform The Evaporative Emission System Leak Test1.0 Hr.111128B2010-2011 Fusion And Milan: Check DTCs, Remove And Inspect The Evaporative Emission Canister, Replace If Necessary, And Replace The Evaporative Emission Canister Purge Valve Includes Time To Perform The Evaporative Emission System Leak Test1.0 Hr.111128B2009-2011 Escape And Mariner: Check DTCs, Remove And Inspect The Evaporative Emission Canister, Replace If Necessary, And Replace The Evaporative Emission Canister Purge Valve Includes Time To Perform The Evaporative Emission System Leak Test1.2 Hrs.MT111128 For Any Additional Diagnosis Or Repair Related to Pin Point Test HX Use SLTS Operations If Available Or Actual Time.