P0105: Manifold pressure / barometric pressure sensor signal is abnormal
MAP / barometric pressure circuit malfunction
Severity: Inspect soon
TroubleCodes.net lists reduced engine power, hesitation, hard starting and higher fuel use for P0105, so get it checked soon rather than ignoring it.
P0105 in short
P0105 means the engine computer saw a manifold absolute pressure (MAP) or barometric pressure signal that is abnormal or does not match throttle position. Vacuum leaks, a faulty MAP or related sensor, or wiring faults are the usual causes. Expect hesitation or reduced power; get it checked soon.
The MAP sensor tells the computer how much air pressure is in the intake manifold. The computer compares that signal with what the throttle position says it should be.
If the two do not agree, or the voltage is outside the normal range, it stores P0105. The title says circuit malfunction, so TroubleCodes.net suggests checking the wiring and reference voltage as well as the sensor.
Most likely causes
These are general causes for this code across vehicles. None is specific to one make or model.
Cause 1: Vacuum leak at a hose or gasket
Common general cause- Why it ranks here
- TroubleCodes.net lists vacuum leaks in hoses or gaskets first, and a leak changes the manifold pressure the sensor reports.
- What would change this
- Rises if a hose is cracked or disconnected, or the signal changes when the hose is moved. Falls if all hoses are sound.
Cause 2: Faulty MAP, barometric, MAF or throttle position sensor
Common general cause- Why it ranks here
- TroubleCodes.net names a defective MAP, MAF, BARO or TPS sensor, because the computer compares them with each other.
- What would change this
- Rises if the MAP voltage does not change smoothly when vacuum is applied. Falls if it responds from about 1 volt to 5 volts as described.
Cause 3: Wiring, connector or ground fault at the sensor
Common general cause- Why it ranks here
- TroubleCodes.net lists open or short circuits, corrosion and a lost ground, and says the wording points to circuit problems.
- What would change this
- Rises if reference voltage or ground is missing at the sensor connector. Falls if both are present.
Cause 4: Clogged catalytic converter
Possible — needs testing- Why it ranks here
- TroubleCodes.net lists a clogged catalytic converter, but only as a less common cause that needs checking.
- What would change this
- Rises if the exhaust is restricted and the code returns with a good sensor. Falls if exhaust flow is normal.
Cause 5: Engine computer fault
Possible — needs testing- Why it ranks here
- TroubleCodes.net calls PCM failure rare, so it comes last.
- What would change this
- Rises only after wiring and sensors test good. Falls if any other cause is found.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Read all stored codes and the freeze-frame data with the ignition on and engine off, and note any other airflow or throttle codes.
IfOther airflow or throttle codes are stored
It meansLook at the shared sensors and wiring.
IfOnly P0105 is stored
It meansLook for leaks and then test the sensor.
Step 2: Check the reference voltage and ground at the MAP sensor connector, and look over hoses, the air filter and connectors.
Warning:Back-probe connectors gently and keep the meter leads from shorting adjacent pins, which can damage the sensor circuit or computer.
IfReference voltage or ground is missing, or a hose is loose
It meansA wiring or leak fault is likely.
IfEverything checks out
It meansTest the sensor response with vacuum.
Step 3: Apply vacuum to the MAP sensor with a hand pump and watch the voltage.
Warning:Do not apply more vacuum than the sensor spec allows, and keep the engine off so you are not working near moving parts.
IfVoltage does not move smoothly between roughly 1 and 5 volts
It meansThe MAP sensor is suspect.
Points to: Faulty MAP, barometric, MAF or throttle position sensor
IfVoltage is smooth
It meansLook for an intermittent fault or a clogged converter.
Symptoms
- Check engine light on
- Reduced engine power
- Hesitation when accelerating
- Hard starting or higher fuel use
How to fix
Step 1: With the engine off and cool, look over visible vacuum hoses and the air filter for damage or loose connections.
Parts and cost context
- Vacuum hoses and intake leaks:Hoses are often the cheapest fix. Find the leak before buying parts. Labour varies; get a quote.
Labor varies by vehicle and shop; get a quote before you approve a repair.
Compare used part prices on PartPriceGuideOn your vehicle
NissanYour car
1997 · Pathfinder
Supported by vehicle dataNissan bulletin NTB97001 says P0105 (with P1105) stored in the engine control module with the lamp on may be caused by a sticking MAP/baro switch solenoid valve. Whether it is still current is not verified.
NTB97001Status unverified
Nissan bulletin: warning lamp with P1105 or P0105 may trace to a sticking MAP/baro switch solenoid valve
1997pathfinder · issued · NHTSA 51294
Nissan bulletin NTB97001 for the 1997 Pathfinder. The summary says the warning lamp is on with P1105 and/or P0105 stored, and that the cause may be a sticking MAP/baro switch solenoid valve. Only the NHTSA summary was read, not the full bulletin; the summary does not give the repair.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
Related codes
All Air metering (MAF, MAP and intake air temperature) codes
P0105 questions
Is it safe to drive with P0105?
Usually short trips are possible, but TroubleCodes.net lists reduced power and hesitation, so have it checked soon.
Sources and review
- P0105 trouble code
- NTB97001: Nissan bulletin: warning lamp with P1105 or P0105 may trace to a sticking MAP/baro switch solenoid valve
- On-Board Diagnostic Trouble Codes (generic code title list)
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
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