Engine - MIL ON/DTC's P0101/P1857
01 MIL on (Mass airflow sensor DTCs P0101, P1857)
24 10 21
2021640/2
June 2, 2010
Supersedes Technical DIAGNOSIS AND REPAIR Group 24 number 09-22 dated October 2, 2009 for reasons listed below.
Affected Vehicles
Condition
^ MIL on.
^ Engine has some reduced performance without significant loss of power or stalling.
Technical Background
DTCs related to Mass Air Flow (MAF) Sensor G70 and fuel trim faults can be related to (but not limited to) the following conditions:
^ False intake air or dirty air filter element.
^ MAF Sensor fault. Possible fault entries associated with this condition:
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^ DTC 16485 (P0101 Mass or Volume Air Flow Circuit Range/Performance).
^ DTC 16265 (P1857 Load Signal Error Message from Engine Control module).
Production Solution
No measures necessary.
Service
1. Ensure one of the previously listed DTCs is logged.
2. Check air filter installation. The air filter must be the factory air filter element that is clean, dry and properly seated in the air box assembly. See
ElsaWeb for vehicle-specific instructions.
3. Delete DTCs and test drive vehicle between 50 60 mph for approximately 5 to 10 minutes, keeping speed as constant as possible.
4. After the test drive, observe MVB 214, value 3 in ECM address word 01. MVB 214 value 3 must be between 0.89 and 1.11.
If the value is outside the specified range, replace MAF Sensor G70.
Tip: The replacement of MAF Sensor G70 is permitted only if one of the above fault entries is logged and ECM measuring value block (MVB) 214,
value 3 is outside of the specified range.
5. Print MVB 214 and include printout with warranty part for verification at the Warranty Parts Return Center (WPRC).
6. After the MAF Sensor replacement, perform a road test to check for correct values in MVB 214, value 3.
Warranty
Additional Information
More information on this system can be found in the following resources:
^ ElsaWeb: TSB 2010064 24 Engine, Intake Manifold Mounting Bolt Torque.
^ ElsaWeb: TSB 2014753 01 MIL on, gasoline quality (DTC P0300 or P030x, lean condition DTCs).
202
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service
manuals for the latest information.
