A Reduced Engine Power message may be displayed on the Driver Information Center of some 2020-2022 Encore GX and 2021-2022 Trailblazer models. The Check Engine MIL may be illuminated and the following DTCs may be set:
- U060F (Lost Communication with Mass Airflow Sensor Bank 1)
- U1346 (Engine Control Module LIN Bus 2)
- P0101 (Mass Air Flow (MAF) Sensor Performance)
- P0102 (Mass Air Flow (MAF) Sensor Circuit Low Frequency)
- P1101 (Intake Air Flow System Performance)
- P14B6 (Mass Air Flow Sensor Signal Message Counter Incorrect)
These conditions may be caused by a possible broken wire in the harness in circuits 492 of the multifunction intake air sensor (MAF sensor). Check the zip-tie at the retainer of the wiring harness. (Fig. 13) If the zip-tie is pulled too tight, the wiring may break when the harness flexes during acceleration.
Fig. 13
The zip-tie is located at the 2nd retainer back from the multifunction sensor. Check the tightness of the zip-tie with the engine running. Wiggle or pull the harness to identify if a break is possible inside the harness.
TIP: If there is internal damage to the harness, prior to the repair below refer to #PIE0682: Engineering Information – Request for Pictures of Broken Wire in the Harness Between the ECM and Multifunction Sensor (MAF Sensor), DTC’s U060F,U1346, P0101, P0102 and/or P1101 Set. This Engineering Information (EI) does not require the technician to call an engineer; only to submit the description of the issue with the PIE number and photos using the Field Product Reporting (FPR) App. Photos are requested of the damaged clip from the engine side (Fig. 14, #1) and the MAF sensor side. (Fig. 14, #2)
Fig. 14
Repair any broken circuits following the wire-to-wire repair for the multifunction intake air sensor (MAF sensor) in the appropriate Service Information. Be sure to rewrap the wiring harness as required to protect it from future damage. It’s recommended to replace all the wires in the harness using the pigtail part numbers listed in Bulletin #22-NA-008.
– Thanks to Frank Jakubiec
