MAP Sensor Signal Voltage Below Normal Range
What does KOHLER-COMMAND-P0107 mean?
The KOHLER-COMMAND-P0107 (Kohler Command EFI) diesel fault code means: MAP Sensor Signal Voltage Below Normal Range. This is a moderate severity code.
Common Symptoms
- Engine cranks but runs rough or surges at idle and under load
- EFI fault code blinks from the LED on the engine or displays on the mower dash
- Engine may start and then stall shortly after reaching operating temperature
- Black smoke or noticeably rich exhaust smell under load
- Engine hesitates or bogs when blades are engaged or when climbing hills
- Fuel consumption seems higher than normal for the job being done
- Engine may go into a reduced-power or limp mode, cutting top RPM
Probable Causes (Ranked by Likelihood)
- MAP sensor signal wire open circuit or broken connector pin at the sensor harness Very Likely
- MAP sensor signal wire shorted to ground in the harness between sensor and ECM Very Likely
- Failed MAP sensor with internal short pulling signal voltage below 0.2V Likely
- Corroded or backed-out connector at the MAP sensor plug causing intermittent loss of signal Likely
- ECM 5V reference supply wire damaged or shorted, starving the sensor of supply voltage Possible
- Damaged ECM with failed MAP input circuit, though this is uncommon without harness damage first Less Likely
Step-by-Step Diagnostic Procedure
Start by visually inspecting the MAP sensor and its connector. The MAP sensor on Kohler EFI engines is typically mounted on the intake manifold near the throttle body. Look for cracked insulation, chafed wires, melted spots from exhaust heat, or a connector that has popped partially out of its lock.
Unplug the MAP sensor connector and inspect all three terminals: 5V reference, signal, and ground. Look for green corrosion, bent pins, or moisture inside the connector. Clean with electrical contact cleaner if you see any corrosion.
With the key ON and engine OFF, use a multimeter set to DC volts. Back-probe the 5V reference wire at the sensor connector (check your engine wiring diagram for the correct pin, but it is typically the red or pink wire). You should read 4.8V to 5.2V. If you read 0V or less than 4V, the reference circuit from the ECM is damaged or shorted.
Still with key ON and engine OFF, back-probe the signal wire at the connector. A good MAP sensor at rest (engine not running, key on) should read approximately 3.5V to 4.5V representing atmospheric pressure. A reading below 0.2V confirms the P0107 condition is present right now.
Check the ground wire at the sensor by measuring resistance from the sensor ground pin back to the engine block ground. You want less than 0.5 ohms. High resistance here can distort sensor readings even if voltage appears present.
If the reference voltage is good and the ground is good but the signal is still below 0.2V, disconnect the sensor and measure the signal voltage again at the harness connector with the sensor unplugged. If the voltage rises to 5V or near it with the sensor disconnected, the sensor itself has an internal short to ground and needs to be replaced.
If the signal voltage stays at 0V even with the sensor disconnected, trace the signal wire from the sensor connector back toward the ECM looking for a pinch point, a rub-through spot, or a chafed section touching the frame or engine block. Repair or replace the harness section as needed.
If you have access to the Kohler PCM diagnostic tool, connect it and check live MAP sensor data. A live reading below 0.5V with the engine off confirms sensor or circuit fault. This tool also lets you clear the DTC after repair to confirm the fix.
Frequently Asked Questions
What does Kohler Command code P0107 mean?
P0107 means the ECM is reading a voltage below the expected range on the MAP sensor signal wire. The MAP sensor measures air pressure in the intake manifold so the ECM can calculate how much fuel to inject. When that signal drops below roughly 0.2V, the ECM cannot trust it and sets P0107. The most common causes are a broken or shorted wire in the sensor harness or a failed sensor.
Can I still mow with a P0107 code showing?
You can usually get the engine started and run the mower, but expect rough running, surging, and reduced power. The ECM will substitute a default fuel value when it loses the MAP signal, which often runs the engine rich. Running in this condition for extended periods can foul the spark plugs and waste fuel. Get it diagnosed before your next full mowing day if possible.
How much does it cost to fix P0107 on a Kohler EFI engine?
If the sensor itself is bad, replacement MAP sensors for Kohler EFI engines run about $25 to $60 for the part. If the harness or connector is the problem, a pigtail repair kit is usually under $15. Doing it yourself the total is typically under $90. A dealer or shop will add labor, bringing the total to roughly $80 to $200 depending on how much wiring work is involved.
Will the mower keep running or shut down with this code?
Most Kohler EFI systems will keep the engine running on a substitute fuel map rather than shutting it down for P0107 alone. The engine will likely run rough and may have reduced power, but a hard stall from this code alone is not common. If you also have a rough start or stall, check for related codes like P0108 or P0068 that could indicate a bigger problem.