P1128
MAP Sensor Value Lower Than Expected
2016-2021 Honda Civic 2.0L I4
Moderate SeverityPowertrain
Description
The MAP sensor reading is lower than expected for current conditions.
Symptoms
- CEL
- Poor performance
- Lean condition
- Hesitation
- Rough idle
Common Causes
- Vacuum leak
- Faulty MAP sensor
- Clogged vacuum line
- Faulty PCM
Diagnostic Steps
- Check for vacuum leaks
- Test MAP sensor
- Inspect vacuum line
- Compare readings
Repair Notes
Fix vacuum leak or replace MAP sensor.
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1128 on Other Vehicles
Common Questions
What does code P1128 mean on a 2016-2021 Honda Civic?
P1128 stands for "MAP Sensor Value Lower Than Expected". The MAP sensor reading is lower than expected for current conditions.
What are the symptoms of P1128 on a Honda Civic?
Common symptoms of P1128 include: CEL, Poor performance, Lean condition, Hesitation, Rough idle.
What causes P1128 on a 2016-2021 Honda Civic?
Common causes of P1128 include: Vacuum leak, Faulty MAP sensor, Clogged vacuum line, Faulty PCM.