Lagonda 3.5-litre C1206 Engine Trouble Code
What is Lagonda 3.5-litre C1206?
Lagonda 3.5-litre C1206 indicates potential catalytic converter failure. If completely failed, your vehicle may not run properly and fuel economy will suffer significantly. Average replacement cost is $2,000–$2,140. This repair requires professional service and should not be delayed.
C1206 on the Lagonda 3.5-litre
In cold climates, Lagonda 3.5-litre vehicles frequently log C1206 during the first winter of ownership. Condensation inside the throttle body creates a temporary short circuit in the position sensor wiring, which clears once the engine warms up — but the fault code remains stored.
Code Information
| Code Type: | OBD-II Chassis (C) Trouble Code |
| System: | Chassis |
| Vehicle: | Lagonda 3.5-litre |
| Brand: | Lagonda |
| Model: | 3.5-litre |
| Code: | C1206 |
C1206 Lagonda 3.5-litre Symptoms
Check Engine Light
Illuminated Lagonda 3.5-litre dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Lagonda 3.5-litre
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Lagonda 3.5-litre
Increased Emissions
Failed emissions test due to C1206
C1206 Code Structure
Understanding what each digit means in the C1206 chassis trouble code:
| C | 1 | 2 | 0 | 6 |
|---|---|---|---|---|
| Chassis Code | Fuel And Air Metering | Manifold Absolute Pressure/Barometric Pressure Circuit High Input | Cold Start Injector 1 Malfunction | Ignition Coil A Primary/Secondary Circuit Malfunction |
How to Fix Lagonda 3.5-litre C1206
Diagnostic Steps:
The catalytic converter has oxygen sensors before and after it. When warm and in closed-loop mode, the upstream O2 sensor reading should fluctuate, while downstream should remain steady.
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:
C1206 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.
Lagonda 3.5-litre C1206 Repair Cost
PCV system overhaul on the Lagonda 3.5-litre — which resolves oil-mist contamination of the MAF sensor — costs $100–$200. The MAF sensor should be cleaned ($15–$25 DIY) or replaced ($80–$150) at the same time to ensure accurate fuelling after the fix.
C1206 Description
C1206 engine trouble code is related to Ignition Coil A Primary/Secondary Circuit Malfunction.
Main Cause
The primary reason for C1206 OBD-II Engine Trouble Code is: Manifold Absolute Pressure/Barometric Pressure Circuit High Input.
Common C1206 Misdiagnosis on the Lagonda 3.5-litre
Fuel injector replacement is over-prescribed on the Lagonda 3.5-litre for C1206 when the actual fault is a weak fuel pump. Low fuel rail pressure causes lean misfire that looks identical to injector failure in static scan data without a live fuel pressure test.
DIY Repair Guide: C1206 on Lagonda 3.5-litre
The coolant temperature sensor on the Lagonda 3.5-litre is a straightforward DIY item (difficulty 2/5). Have a drain tray ready for the small amount of coolant that spills when the sensor is removed. Top up the cooling system afterwards and check for air pockets.
Preventing C1206 on the Lagonda 3.5-litre
Spark plug replacement at the manufacturer's interval — typically 30,000–60,000 miles depending on plug type — is the single most cost-effective preventive maintenance item for avoiding C1206 on the Lagonda 3.5-litre.
Frequently Asked Questions — Lagonda 3.5-litre C1206
A: Yes. Some fault conditions, particularly those involving EVAP system leaks or marginal sensor readings, store codes without producing noticeable drivability symptoms. These are called memory faults and still need to be addressed because they will eventually cause performance issues.