Honda-specific code — factory diagnostic data| DTC Data Sheet | |
| Code | P0102 — MAF sensor circuit low voltage |
| Primary vehicle covered | 2010 Honda Insight (ZE2, 1.3L LDA IMA hybrid) |
| System | Powertrain / Fuel & Air Metering |
| Fault type | Circuit Low |
| Honda meaning | MAF (mass air flow) sensor circuit voltage below calibrated threshold |
| Scan tool | Honda HDS (or aftermarket with Honda engine coverage) |
| Failure criterion on HDS | MAF SENSOR reads about 0 g/s, or 0.1 V or less, with ignition ON (II) after 2 seconds |
| MAF power fuse | No. 12 IMA (10 A) in the under-dash fuse/relay box |
| MAF 5P connector — pin 5 | Power feed from No. 12 IMA fuse (battery voltage, KOEO) |
| MAF 5P connector — pin 3 | Signal wire to PCM B30; 190–210 kΩ to body ground when sensor disconnected |
| PCM pin | B30 on PCM connector B (44P) |
Scope note. The fuse name (“No. 12 IMA”), the 10 A rating, pin numbers (MAF 3 and 5, PCM B30), and the 190–210 kΩ signal-line resistance spec are specific to the 2010 Honda Insight (ZE2) with the 1.3L LDA IMA hybrid powertrain. Other Honda engines with MAF sensors use the same diagnostic logic but different fuse names, PCM pin assignments, and sometimes different resistance specs — always verify against the wiring diagram for your specific vehicle.
P0102 means the PCM is reading the MAF (mass air flow) sensor signal at or near zero volts — specifically, about 0 g/s or 0.1 V or less on the HDS DATA LIST. A healthy MAF reads a positive air-mass value any time the engine is running; even with key-on-engine-off (KOEO) the baseline is small but non-zero if the sensor is powered. A reading stuck at zero means the sensor isn’t powered, the signal wire is shorted to ground, the sensor is internally dead, or (rare) the PCM driver has failed. Honda’s procedure isolates which of those it is with a fuse check, a power-feed test, a signal-line resistance measurement, and PCM wiring continuity checks.
Decode any Honda Insight VIN — free recalls, specs & safety ratings — free VIN decoder with NHTSA data
P0102 Honda Insight Quick Answer
On the 2010 Insight, P0102 almost always resolves at the No. 12 IMA (10 A) fuse or the MAF power feed. Check the fuse first — if blown, a short downstream pulled it. Power feed at MAF 5P pin 5 should be battery voltage with KOEO; if not, the fuse or the wire between fuse and sensor is the fault. If both are good, measure 190–210 kΩ between MAF pin 3 and body ground with the sensor disconnected; out of spec = move to PCM wiring continuity. In spec = substitute a known-good MAF and retest at 2,000 RPM.
The Diagnostic Procedure
Tools: Honda HDS (or aftermarket with Honda engine coverage), DMM with kΩ range, wiring diagram. Do not replace the MAF on a guess — a blown 10 A IMA fuse produces the same symptom as a dead sensor but a fraction of the cost to fix.
- Confirm the fault is current. Turn ignition ON (II) and wait 2 seconds. Check MAF SENSOR in the HDS DATA LIST.
→ About 0 g/s or 0.1 V or less: fault is current, proceed to step 2.
→ Normal reading (non-zero): intermittent fault. Check MAF and PCM connector tension, inspect wire routing for chafe points, re-seat both connectors and monitor. - Check the No. 12 IMA (10 A) fuse in the under-dash fuse/relay box.
→ Fuse blown: something downstream pulled the fuse. Repair the short between the MAF sensor and the 10 A fuse, then fit a new fuse. Reset PCM and retest.
→ Fuse OK: proceed to step 3. - Check power feed at the MAF connector. Turn ignition OFF. Disconnect the MAF/IAT 5P connector. Turn ignition ON (II). Measure voltage between MAF 5P connector pin 5 and body ground.
→ Battery voltage present: power feed OK, proceed to step 4.
→ No voltage: open in the wire between the 10 A fuse and the MAF sensor. Trace through the under-dash fuse box bulkhead connector to the engine bay harness, looking for chafe or disconnection. Repair and retest. - Measure signal-line resistance. Ignition OFF. With the MAF still disconnected, measure resistance between MAF 5P pin 3 and body ground. Honda spec: 190 to 210 kΩ.
→ In spec: the signal wire and PCM driver are electrically healthy end-to-end — the fault is most likely the MAF sensor itself. Jump to step 7.
→ Out of spec: proceed to step 5 (signal-line PCM check). - Jump the SCS line with HDS, then disconnect PCM connector B (44P). The SCS jump is mandatory before any probing on PCM pin B30 — it protects the PCM driver from back-feeding.
- Check PCM signal-wire integrity. First measure continuity between PCM connector pin B30 and body ground.
→ Continuity to ground: short in the signal wire between PCM B30 and MAF pin 3. Repair and retest.
→ No continuity: check continuity between MAF 5P pin 3 and PCM pin B30.
→ Continuity present: wiring is clean end-to-end. Move to PCM update/substitute path (step 8).
→ No continuity: open in the signal wire. Repair and retest. - Substitute a known-good MAF/IAT sensor. Reconnect everything. Clear the DTC. Start the engine and hold 2,000 RPM in Park or Neutral without load.
→ P0102 does not return: original MAF was faulty. Replace the MAF/IAT sensor permanently. Done.
→ P0102 returns: the MAF isn’t the cause (unexpected given the step-4 spec was in range). Proceed to PCM update path (step 8). - PCM software update, then substitute. Reconnect all connectors. Update the PCM to the latest Honda software if not already current.
→ P0102 clears after update: repair verified.
→ P0102 persists: substitute a known-good PCM. If the substitute clears the fault, replace the original PCM permanently. - Clear, reset, and verify. Reset the PCM with HDS. Perform the PCM idle learn procedure. Drive through the freeze-frame range. Verify no pending or confirmed DTCs and OBD STATUS shows PASSED.
Professional tip. The Insight’s MAF fuse is labeled “No. 12 IMA” in the under-dash box — non-hybrid Honda service information will call it something different, so don’t look for a generic “engine” or “MAF” fuse label. The “IMA” prefix here is Honda’s naming convention on the IMA hybrid platform; the fuse still powers the conventional MAF circuit regardless.
Common Causes on the 2010 Insight ZE2
Ranked by real-world frequency, mapped to the step that isolates each:
- Blown No. 12 IMA (10 A) fuse with a short downstream — isolated by step 2. Most common P0102 on this platform. A chafed wire, a water-damaged connector, or a shorted MAF internally can pop the fuse.
- Failed MAF/IAT sensor (internal element burned out, hot-wire contaminated by oil vapor or dirt) — isolated by step 7 via substitution when signal-line resistance measures in spec.
- Open in the power feed between the 10 A fuse and MAF pin 5 — isolated by step 3. Bulkhead connector corrosion is the typical culprit.
- Short in the signal wire between PCM B30 and MAF pin 3 — isolated by step 6. Harness chafe against a bracket or heat damage near the intake.
- Open in the signal wire between PCM B30 and MAF pin 3 — isolated by step 6. Broken wire at a pass-through grommet or a backed-out pin.
- Corroded or backed-out MAF/PCM connector terminals — produces intermittent P0102 that clears on wiggle tests.
- PCM calibration or driver failure — last resort. Apply the latest Honda PCM software update before substituting a known-good module.
Severity & Driving
P0102 is a drivability fault but not immediately dangerous. With the MAF reading zero, the PCM falls back to a default fuel-and-ignition map based on throttle position and engine speed — the engine will run but expect rough idle, poor throttle response, elevated fuel consumption, and occasional stalling under load. On the IMA hybrid, the MAF signal also feeds into the hybrid assist/regeneration strategy, so expect degraded hybrid behavior and noticeably worse fuel economy until the code is cleared. Continued driving with P0102 will not damage the engine, but the fault tends to compound — a blown fuse often indicates an ongoing short that will recur until the wiring is inspected.
FAQ
What should the MAF read when working properly on a 2010 Insight?
At idle (after 2 seconds KOEO), the MAF reads a small non-zero value; at idle with engine running, roughly 2–4 g/s; at 2,000 RPM unloaded in neutral, roughly 8–12 g/s on the 1.3L LDA. Honda’s failure criterion for P0102 is specifically “about 0 g/s, or 0.1 V or less” with ignition ON (II) for 2 seconds.
Can I clean the MAF sensor instead of replacing it?
Carefully — only with MAF-specific aerosol cleaner (never throttle body or carb cleaner, which damage the sensor element). Clean the hot-wire element with short sprays held about 10 cm away. If the sensor is truly shorted to ground internally (which is what causes P0102 circuit-low), cleaning won’t help — but a dirty sensor can cause drivability issues that mimic MAF faults without setting a circuit DTC.
The fuse keeps blowing after I replace it. Now what?
That confirms an active short somewhere between the fuse and the MAF — stop replacing fuses and trace the wire. The short is usually at a chafe point near a bracket, the bulkhead grommet, or inside a damaged connector. Disconnect the MAF first and retest the fuse; if it still pops, the fault is between the fuse and the MAF connector. If it only pops with the MAF connected, the sensor itself is internally shorted — replace the MAF.
Is “No. 12 IMA” fuse the same as the MAF fuse on other Hondas?
Functionally yes — it’s the 10 A power feed for the MAF circuit — but the fuse box position and label are Insight-specific. Civic, Fit, CR-V, and Accord use different fuse box layouts and different fuse labels. Always use the fuse box diagram for your exact vehicle.
Why does Honda want me to update the PCM software before replacing it?
Honda occasionally releases PCM calibrations that affect how MAF circuit faults are detected and cleared. A small percentage of persistent P0102 cases turn out to be calibration-related, not hardware failures. Applying the update before swapping a known-good PCM avoids wasting a module on a fix that’s free.