Packard 400 U1859 Engine Trouble Code
What is Packard 400 U1859?
The Packard 400 U1859 check-engine light can indicate issues ranging from minor (loose gas cap) to serious (catalytic converter failure). Professional diagnostic scanning at a dealer or shop will identify the exact cause and required repairs.
U1859 on the Packard 400
On the Packard 400, a secondary air injection pump that has seized due to moisture ingress is a common trigger for U1859. The fault is usually only present on cold starts and clears itself after two to three warm-up cycles, making it easy to overlook.
Code Information
| Code Type: | OBD-II Network (U) Trouble Code |
| System: | Network |
| Vehicle: | Packard 400 |
| Brand: | Packard |
| Model: | 400 |
| Code: | U1859 |
U1859 Packard 400 Symptoms
Check Engine Light
Illuminated Packard 400 dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Packard 400
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Packard 400
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 400 U1859
Diagnostic Steps:
Check if fuel pump primes when key is turned to ON. Measure fuel pressure and verify bright white-blue spark at all plugs. Also verify mechanical timing alignment.
Repair Solution:
VSS concerns may stem from noisy input signals caused by RFI/EMI from ignition wires, charging circuits, or aftermarket equipment. Verify VSS reads 0 mph when transmission is in Park.
Technical Notes:
U1859 DTC specifically relates to camshaft timing. When cam timing is over-retarded, the check-engine light illuminates and this code sets. Verify VCT solenoid operation and check for contamination.
Packard 400 U1859 Repair Cost
For Packard 400 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 400
On the Packard 400, the VANOS (variable camshaft timing) solenoid is routinely replaced for U1859 when the actual issue is oil pressure insufficiency. No solenoid will operate correctly if the oil pressure required to actuate the VVT phaser is not present.
DIY Repair Guide: U1859 on Packard 400
After any repair that involved disconnecting the battery on the Packard 400, the power window, steering angle sensor, and transmission adaptive values all require a reset drive cycle. Skipping this can cause false fault codes — including U1859 — for the first two to three start cycles.
Preventing U1859 on the Packard 400
Inspecting the Packard 400 wiring harness conduit grommets annually — especially the floor pan grommet — costs nothing and takes 10 minutes. Catching moisture ingress early eliminates the most common electrical trigger for U1859 on this model.
Frequently Asked Questions — Packard 400 U1859
A: It depends on the severity. If the check-engine light is steady, it is generally safe to drive to a workshop within the next few days. If the light is flashing, pull over safely as soon as possible — a flashing light indicates an active misfire that can cause expensive catalytic converter damage within minutes.