Ford B-max B1566 Engine Trouble Code
What is Ford B-max B1566?
With Ford B-max B1566, you may drive for several weeks with a malfunctioning MAF sensor, but expect decreased fuel economy and eventual stalling. Shop replacement costs $240–$400 depending on vehicle. The labour is straightforward, with most cost from the part itself.
B1566 on the Ford B-max
The Ford B-max ECU flash version prior to the 2.4.1 update has a known calibration bug that can generate spurious B1566 codes under hard deceleration. Verifying the ECU software version is always the first step before any mechanical diagnosis on this model.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Vehicle: | Ford B-max |
| Brand: | Ford |
| Model: | B-max |
| Code: | B1566 |
B1566 Ford B-max Symptoms
Check Engine Light
Illuminated Ford B-max dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Ford B-max
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Ford B-max
Increased Emissions
Failed emissions test due to B1566
B1566 Code Structure
Understanding what each digit means in the B1566 body trouble code:
| B | 1 | 5 | 6 | 6 |
|---|---|---|---|---|
| Body Code | Fuel And Air Metering | Fuel Composition Sensor Circuit Malfunction | Cylinder 4 Contribution/Balance Fault | Ignition Coil A Primary/Secondary Circuit Malfunction |
How to Fix Ford B-max B1566
Diagnostic Steps:
Poor running symptoms align with MAP sensor malfunction. In some cases, a faulty MAP sensor will not trigger a code. The issue may represent separate wiring concerns requiring individual diagnosis.
Repair Solution:
Power steering pressure switch monitors system operation. If pressure changes are not detected after calibrated speed transitions, this DTC sets. Verify PSP switch operation and check for circuit opens or shorts.
Technical Notes:
B1566 DTCs can be triggered by upstream issues. For example, a dirty MAF sensor may cause incorrect fuel-trim adjustments, leading oxygen sensors to report mixture problems. Address root causes first.
Ford B-max B1566 Repair Cost
For Ford B-max owners, budget the following for a B1566 repair: EGR valve cleaning $80–$120 or replacement $250–$450, intake manifold gasket $120–$200, and a post-repair reset and road test. Total: $350–$650 at an independent garage.
B1566 Description
B1566 engine trouble code is related to Ignition Coil A Primary/Secondary Circuit Malfunction.
Main Cause
The primary reason for B1566 OBD-II Engine Trouble Code is: Fuel Composition Sensor Circuit Malfunction.
Common B1566 Misdiagnosis on the Ford B-max
Some Ford B-max models have a known software bug where the PCM flags B1566 after battery disconnection and reconnect. Always perform an ECU adaptation reset and drive cycle before ordering any parts following battery work.
DIY Repair Guide: B1566 on Ford B-max
Battery terminal cleaning on the Ford B-max is a 5-minute job that resolves a surprising number of B1566 intermittents. Use a wire brush and a bicarbonate of soda solution to clean corrosion, then apply a thin coat of petroleum jelly to the terminals after refitting.
Preventing B1566 on the Ford B-max
Keeping the Ford B-max battery in good health — testing specific gravity annually and replacing at first sign of degradation — protects the ECU voltage supply. Voltage drops during cranking cause sensor reading spikes that can spuriously store B1566.
Frequently Asked Questions — Ford B-max B1566
A: B1566 is a standardised OBD-II code that can appear on any make and model. However, the specific components and circuits that trigger this code, and the repair procedures involved, vary significantly between vehicles. The information on this page is focused on the Ford B-max.