OBD-II trouble code
P0104: Mass or Volume Air Flow Circuit Intermittent
SAE J2012 names an intermittent mass-or-volume airflow circuit. The 2008 Pontiac G6 procedure does not store P0104. Its intermittent aid is a 15-ohm ignition-feed fault that can move the MAF reading by 60 g/s.
Quick facts
- System
- Powertrain
- Category
- Fuel & Air
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $200 – $400
- DIY difficulty
- Intermediate DIY
Browse every code in P0100–P0199, or start from the full code library.
What does P0104 mean?
P0104 is Mass or Volume Air Flow Circuit Intermittent in SAE J2012 APR2002. Intermittent means the signal drops in and out rather than staying above or below the hard limit. The standard does not give a hertz or volt limit for it. A calibration that only publishes high and low codes may never store P0104 for the same wire.
The 2008 Pontiac G6 procedure for the MAF sensor is written for P0102 and P0103. It does not list P0104. What it does say about a fault that comes and goes is in the diagnostic aids: a steady or intermittent high resistance of 15 ohms or greater on the ignition-1 circuit increases the MAF signal by as much as 60 g/s, and a slightly greater resistance can make the signal cease. A MAF signal shorted to the intake-air-temperature signal can raise or lower the MAF value the ECM uses, depending on temperature and load, and it can make the IAT parameter fluctuate rapidly. The procedure points intermittent diagnosis at the GM routine Testing for Intermittent Conditions and Poor Connections.
The G6 hard limits, for comparison when a dropout becomes a hard code, are under 10 Hz for more than 5 seconds for P0102 and over 11,000 Hz for more than 5 seconds for P0103. Normal frequency on that car is near 1,700 Hz at idle to near 9,500 Hz at full load. Idle verification is 1,700–3,200 Hz depending on coolant temperature.
The 1999 Ford PCED DTC list in section 4 does not include P0104. Its MAF entries are P0102 and P0103. An intermittent complaint on a vehicle covered by that manual is diagnosed with whichever of those two the freeze frame actually crossed, plus the connection checks that manual prints for the MAF circuits.
GM's 2008 GRP09 sheet publishes P0102 at or below 900 Hz and P0103 at or above 14,500 Hz. It does not publish a P0104 row. A frequency that touches those lines intermittently is still those codes on that sheet.
Common causes
- On a 2008 G6, intermittent resistance of 15 ohms or more in the ignition-1 feed to the MAF, which can add as much as 60 g/s
- On that G6, the MAF signal shorted to the IAT signal, which the aid says can make both parameters swing
- A connector or terminal fault found with the G6 intermittent-connection routine while the frequency is watched, engine running in the bay
- A dropout that reaches the hard limit: under 10 Hz or over 11,000 Hz for more than 5 seconds on the G6, which is then P0102 or P0103
- On GRP09 engines, a signal that intermittently reaches 900 Hz or 14,500 Hz, stored as P0102 or P0103 rather than as P0104
Symptoms
- Malfunction indicator lamp with P0104 on a calibration that uses this code
- On a 2008 G6, a MAF reading that jumps by as much as 60 g/s when the ignition feed is loaded by resistance of 15 ohms or more
- IAT fluctuating rapidly when the MAF signal is shorted to the IAT signal, which is the G6 aid
- A freeze frame that shows either a near-zero frequency or a frequency up at the high limit for only part of the event
- No P0104 entry in the 1999 Ford PCED section 4 list or in the GRP09 parameter sheet
Diagnostic steps
- 1.Confirm the stored code is P0104 and not a hard P0102 or P0103 that was cleared. If the chart for this VIN has no P0104 definition, stop and follow the high or low test it does publish.
- 2.On a 2008 G6, load-test the ignition-1 feed. The aid says 15 ohms or more, steady or intermittent, can raise the signal by as much as 60 g/s, and a bit more resistance can drop the signal out. Measure that feed under load, not with an unloaded continuity beep.
- 3.Watch MAF frequency and IAT together, engine running, vehicle parked. A rapid IAT swing beside a MAF swing is the G6 description of the MAF signal shorted to the IAT signal. Separate those two wires and repair the short the diagram shows.
- 4.Use the G6 intermittent routine: move the connector and the harness while the frequency is on the scan tool, in the bay. The circuit test that proves the wiring, once the fault is present, is the same order as the hard-code procedure. Ignition off for 90 seconds, terminal B under 5 ohms to ground. Ignition on, test lamp from terminal C to ground. Signal terminal A at 4.8–5.2 volts. Those pin letters are the G6 connector.
- 5.Do not road-test with the driver reading the scan tool. If the dropout only happens on the road, record it.
- 6.On a 1999 Ford from that PCED, or on a 2008 GRP09 engine, diagnose the intermittent against P0102 and P0103. GRP09's lines are 900 Hz and 14,500 Hz. The G6's lines are 10 Hz and 11,000 Hz. Do not mix them, and do not apply the G6 pin letters to the other vehicles.
- 7.Replace the sensor after the feed resistance, the signal-to-IAT short, and the connector test have not reproduced the dropout and the hard-code circuit test has passed.
Repair cost
$200 – $400
Once the connector is ruled out, the mass-airflow sensor is about $200 to $400 installed. That is the same sensor job as the hard high-input code.
Estimate your repair
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Open the Repair Cost Estimator with mass airflow sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
Related repairs
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.