U1011

Code

Other U — Network/User

SCP (J1850) Invalid or Missing Data for Engine Air Intake

Brand: Other

Type: U — Network/User

Views: UK: 37 EN: 56 RU: 54

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Open or short in wiring between intake sensors and their control module (MAF, MAP, IAT, throttle).
Faulty MAF, MAP, IAT or related sensor producing invalid data.
Poor or corroded connector or ground at sensor or control module.
SCP (J1850) network fault: damaged bus wiring, poor termination, or short to ground/voltage.
Faulty module that transmits or receives engine air intake data (ECM/PCM or gateway module).
Software/firmware mismatch, incorrect module configuration or failed module programming.

Malfunction Indicator Lamp (MIL) illuminated with U1011 stored.
Poor idle, hesitation, stalling or reduced engine power if intake data is used for fueling/controls.
Stored and/or correlated PID faults such as MAF/IAT/MAP codes (P0101, P0112, etc.).
Intermittent drivability issues or limp-home mode depending on vehicle strategy.
Missing or inconsistent intake-related live data on a scan tool.

Use a capable scan tool to read U1011, freeze frame and live PIDs for MAF, MAP, IAT, throttle position and calculated load.
Check for additional DTCs that point to a specific sensor (P0101, P0102, P0112, etc.).
Visually inspect wiring, connectors and harnesses for damage, corrosion or disconnection at intake sensors and ECM/PCM.
Verify power and ground at the intake sensors and at the receiving module.
Monitor SCP (J1850) bus activity with a scanner or oscilloscope; check for message frequency and noise.
Check bus termination resistors and look for short to battery or ground on the network line.

MAF sensor output: typical airflow in g/s (or frequency/voltage depending on sensor type).
Intake Air Temperature (IAT): degrees Celsius or voltage corresponding to temperature.
Manifold Absolute Pressure (MAP): kPa (or voltage for MAP sensor).
Throttle position: percentage or voltage (0–100% or ~0.5–4.5 V).
SCP (J1850) network: periodic messages containing the above PIDs; message frequency varies by manufacturer (typically periodic updates while engine running).

Connect a scan tool and record freeze frame and live data for MAF, MAP, IAT and throttle while key-on and during running conditions; confirm missing or invalid values.
Check for other related DTCs (P0101, P0112, etc.) to narrow down which sensor or data is involved.
Visually inspect wiring and connectors at the suspected sensor(s) and ECM/PCM for damage, corrosion or loose pins; repair as needed.
Verify sensor supply voltage and ground at each sensor with key-on using a DVOM; compare to expected values from factory data.
If wiring and power/ground are good, test the sensor output (voltage or frequency) while varying engine conditions (or use a known-good sensor).
If the sensor outputs valid signals but the receiving module shows no/invalid messages, capture SCP (J1850) bus signals with an oscilloscope or network-capable scan tool to check for missing messages, noise, or improper levels.
Check and repair bus wiring, connectors and termination resistors if communication faults are found; isolate short circuits and repair open circuits.
If network and sensors check good, verify software calibration levels and perform module reprogramming or replacement per manufacturer procedures.
Clear codes and test drive to confirm the fault does not return; if intermittent, perform wiggle tests on harness and monitor live data.

Intermittent or open wiring/connector problem at MAF or IAT sensors causing missing/invalid data.
Contaminated/damaged MAF sensor producing out-of-range readings.
Lost or corrupted SCP (J1850) bus messages due to wiring damage or missing termination.
Faulty ECM/PCM or other control module that publishes intake data on the SCP bus.