Graham Streak U1859 Engine Trouble Code
What is Graham Streak U1859?
Graham Streak U1859 code can indicate a faulty oxygen sensor, which may eventually damage the catalytic converter (repair cost: $2,000–$2,200). Professional diagnosis costs around $200–$210. Oxygen sensors are often straightforward to replace — check your owner's manual for location and instructions. This issue should be addressed promptly to prevent further damage.
U1859 on the Graham Streak
The Graham Streak has a known weak point in the lambda sensor wiring loom where it passes through the floor pan grommet. Road salt and vibration cause the insulation to crack at this point, creating an intermittent open circuit that stores U1859 without a consistent symptom.
Code Information
| Code Type: | OBD-II Network (U) Trouble Code |
| System: | Network |
| Vehicle: | Graham Streak |
| Brand: | Graham |
| Model: | Streak |
| Code: | U1859 |
U1859 Graham Streak Symptoms
Check Engine Light
Illuminated Graham Streak dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Graham Streak
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Graham Streak
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 Graham Streak U1859
Diagnostic Steps:
Regarding U1859, carefully inspect the wire harness near the intake manifold bracket, best accessed from below near the oil filter. Look for chafing, pinching, or damaged insulation.
Repair Solution:
Gasoline engines use spark plugs to ignite fuel-air mixture. Proper timing ensures the explosion occurs when the piston is positioned correctly. Incorrect plug wire sequencing causes mistimed ignition, resulting in poor performance.
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.
Graham Streak U1859 Repair Cost
On the Graham Streak, secondary air injection pump replacement for a U1859 code runs $350–$600. Because the pump is only active during cold starts, symptoms are easily missed. Requesting a cold-start emissions test at the workshop will confirm whether the pump is operating.
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 Graham Streak
Replacing the PCM/ECU on the Graham Streak for a persistent U1859 is a last-resort action that is often performed prematurely. Statistically, less than 2% of U1859 faults on this platform originate in the ECU; wiring, sensors, and mechanical causes account for the remainder.
DIY Repair Guide: U1859 on Graham Streak
The coolant temperature sensor on the Graham Streak 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 U1859 on the Graham Streak
Scheduled inspection of the Graham Streak air filter every 15,000 miles can prevent the intake restriction that leads to U1859. A blocked filter forces the engine to run rich, stressing the catalytic converter and ultimately storing fault codes.
Frequently Asked Questions — Graham Streak U1859
A: Temporarily clearing U1859 can help determine whether it is intermittent or persistent, but it does not fix the underlying fault. The code will return if the problem is still present. Do not clear codes just before an emissions test without a proper drive cycle.