Packard Custom U1859 Engine Trouble Code
What is Packard Custom U1859?
Packard Custom 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 Packard Custom
A known issue on the Packard Custom is that aftermarket air filter upgrades can inadvertently trigger U1859. High-flow filters alter the intake resonance frequency, causing the MAP sensor to report pressure readings outside factory calibration.
Code Information
| Code Type: | OBD-II Network (U) Trouble Code |
| System: | Network |
| Vehicle: | Packard Custom |
| Brand: | Packard |
| Model: | Custom |
| Code: | U1859 |
U1859 Packard Custom Symptoms
Check Engine Light
Illuminated Packard Custom dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Packard Custom
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Packard Custom
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 Packard Custom 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:
Disconnected, dirty, or fouled spark plugs commonly prevent proper engine operation. Replace spark plugs every season or 25 hours. Verify proper spark plug gap. If plugs are good, check ignition components: spark plug wires, coils, and ignition module.
Technical Notes:
Parts or components should not be replaced based solely on U1859 DTC. Consult your vehicle service manual for proper diagnostic procedures, possible causes, and required testing before replacement.
Packard Custom U1859 Repair Cost
For Packard Custom owners, budget the following for a U1859 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.
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 Packard Custom
Some Packard Custom 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 Packard Custom
When attempting DIY diagnosis of U1859 on your Packard Custom, a smoke machine test is the gold standard for finding vacuum leaks. Rental tools are available from most auto parts stores for $0–$20/day, or you can fabricate a makeshift tester using a hand vacuum pump and soapy water spray.
Preventing U1859 on the Packard Custom
Keeping the Packard Custom 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 U1859.
Frequently Asked Questions — Packard Custom U1859
A: Contaminated or low-octane fuel can temporarily trigger U1859 through knock retard and lean/rich excursion events. If the code appeared shortly after a fill-up at an unfamiliar station, running the tank close to empty and refuelling with premium is a sensible first step.