Code
P1107
MINI
P — Powertrain
Manifold absolute pressure (MAP) sensor - signal too low at idle
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UK: 4
EN: 3
RU: 4
AI status
Completed
Completed
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Causes
- Electrical fault (open/short/poor connection) in MAP sensor circuit
- Failed MAP sensor
- Intake manifold vacuum leak or restricted intake path
- Blocked or disconnected vacuum/boost reference hose (if fitted)
- ECU fault or incorrect sensor reference/ground
Symptoms
- Check Engine Light (MIL) illuminated
- Rough or unstable idle, stalling at idle
- Poor throttle response, hesitation or reduced power
- Increased fuel consumption, black smoke possible
- Possible limp-home mode or reduced turbo/boost control
What to check
- Read and record freeze-frame data and full live MAP sensor trace at key-on idle, during rev, and coast-down
- Compare MAP reading to barometric pressure (engine off, key on) and to expected manifold vacuum at idle
- Scan for additional codes (MAF, IAT, fuel rail pressure, boost control) that may indicate related faults
- Visually inspect MAP connector, wiring harness, and vacuum/boost hoses for damage, corrosion, or disconnection
- Backprobe MAP sensor: verify 5 V reference supply and ground present with key on
- Wiggle test wiring while observing live MAP signal for intermittent changes
Signal parameters
- Sensor supply/reference: 5.0 V (±0.25 V) from ECU (verify on backprobe)
- Sensor ground: near 0 V, low resistance to chassis/ECU ground
- MAP output nominal range: ~0.5–4.5 V depending on manifold absolute pressure
- Typical MAP at idle (naturally aspirated): ~20–40 kPa (approx. 0.5–1.5 V output) — values vary by engine and turbocharging; compare to factory data
- Engine-off/Key-on MAP output should approximate ambient/barometric pressure reading; large discrepancy suggests sensor or wiring fault
Diagnostic algorithm
- Retrieve freeze frame and live data: record MAP voltage/kPa at idle, at higher RPM, and engine-off key-on. Note related sensors (MAF, IAT, BARO).
- Verify symptom and code: confirm code is current and reproducible. Clear code, then re-test to see if it returns.
- Visually inspect sensor, connector, and intake plumbing for damage, oil contamination, or disconnected vacuum lines. Repair as needed.
- With key ON engine OFF, backprobe sensor: confirm 5 V reference and ground. If missing, trace and repair supply/ground to ECU.
- With engine idling, monitor MAP voltage while inducing known changes (slight throttle, a vacuum leak) to confirm sensor responds. If signal stays low/inactive, suspect sensor/wiring.
- Perform continuity and resistance checks from sensor connector to ECU pins to find opens/shorts. Repair wiring or connector faults.
- If wiring and power/ground are good, substitute a known-good MAP sensor or bench-test sensor according to manufacturer procedure.
- Pressure/smoke test intake manifold and boost/vacuum hoses to find leaks that could cause abnormally low MAP at idle. Repair leaks and retest.
- After repairs or replacement, clear codes and verify proper MAP behavior in live data across operating range and confirm no reoccurrence.
- If all above checks pass and symptoms persist, consider ECU diagnosis/programming at dealer level.
Likely causes
- Damaged sensor connector or corroded pins causing low signal
- Broken or pinched vacuum/boost hose to sensor or intake manifold leak at gasket/throttle body
- Failed MAP sensor (internal electronics)
- Supply/reference voltage missing or low (5 V reference)
- Intermittent wiring fault between MAP sensor and ECU
Fault status
Status
MAP sensor signal too low at idle — sensor output voltage/pressure reading lower than expected. Can be caused by wiring/power/ground issues, sensor failure, or intake vacuum/boost problems.
Repair difficulty: Medium
Diagnostic time: 1.0-2.5 hours
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