Hispano Suiza Type 68 U1859 Engine Trouble Code
What is Hispano Suiza Type 68 U1859?
Hispano Suiza Type 68 U1859 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.
U1859 on the Hispano Suiza Type 68
Diesel variants of the Hispano Suiza Type 68 trigger U1859 most often due to swirl flap actuator failure. The plastic actuator arm breaks and the flap defaults to the closed position, causing severe intake restriction and the associated fault flag.
Code Information
| Code Type: | OBD-II Network (U) Trouble Code |
| System: | Network |
| Vehicle: | Hispano Suiza Type 68 |
| Brand: | Hispano |
| Model: | Suiza Type 68 |
| Code: | U1859 |
U1859 Hispano Suiza Type 68 Symptoms
Check Engine Light
Illuminated Hispano Suiza Type 68 dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Hispano Suiza Type 68
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Hispano Suiza Type 68
Increased Emissions
Failed emissions test due to U1859
U1859 Code Structure
Understanding what each digit means in the U1859 network trouble code:
| U | 1 | 8 | 5 | 9 |
|---|---|---|---|---|
| Network Code | Fuel And Air Metering | Engine Oil Temperature Sensor Malfunction | Cylinder 1 Injector Circuit Low | Reverse Input Circuit |
How to Fix Hispano Suiza Type 68 U1859
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:
A/C pressure sensor monitors refrigerant pressure changes. DTC sets when pressure change falls outside calibration. Verify A/C system function, refrigerant charge, and electrical connections.
Technical Notes:
For U1859, verify VCT solenoid operation. Look for stuck or sticking valves caused by contamination. Consult vehicle-specific repair manual for proper component testing procedures.
Hispano Suiza Type 68 U1859 Repair Cost
Replacing the lambda (O2) sensor wiring loom section on the Hispano Suiza Type 68 costs $90–$160 at a body shop or auto-electrician. This is far cheaper than replacing the sensor itself when the sensor is otherwise functional — always inspect wiring before condemning sensors.
U1859 Description
U1859 engine trouble code is related to Reverse Input Circuit.
Main Cause
The primary reason for U1859 OBD-II Engine Trouble Code is: Engine Oil Temperature Sensor Malfunction.
Common U1859 Misdiagnosis on the Hispano Suiza Type 68
Some Hispano Suiza Type 68 models have a known software bug where the PCM flags U1859 after battery disconnection and reconnect. Always perform an ECU adaptation reset and drive cycle before ordering any parts following battery work.
DIY Repair Guide: U1859 on Hispano Suiza Type 68
For the Hispano Suiza Type 68, an EGR valve inspection is a useful DIY step before spending money on diagnosis. Remove the valve (2–4 bolts depending on generation), inspect for carbon build-up, and use carburettor cleaner and a soft brass brush to clean the valve face and seat.
Preventing U1859 on the Hispano Suiza Type 68
The Hispano Suiza Type 68 coolant temperature sensor plays a role in fuel enrichment during warm-up. Replacing it as a precaution at 80,000 miles ($25–$40 DIY) prevents the faulty cold-start enrichment that can lead to U1859.
Frequently Asked Questions — Hispano Suiza Type 68 U1859
A: If your Hispano Suiza Type 68 is within the factory powertrain warranty period (typically 3–5 years or 60,000–100,000 miles depending on region and generation), U1859 repairs caused by component defects should be covered. Bring your service history to the dealer appointment.