Suzuki Splash U1859 Engine Trouble Code
What is Suzuki Splash U1859?
The Suzuki Splash 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 Suzuki Splash
Owners who tow regularly with their Suzuki Splash should pay extra attention to U1859. The additional thermal load placed on the transmission fluid accelerates the degradation of the torque converter clutch solenoid, a frequent secondary cause of this code.
Code Information
| Code Type: | OBD-II Network (U) Trouble Code |
| System: | Network |
| Vehicle: | Suzuki Splash |
| Brand: | Suzuki |
| Model: | Splash |
| Code: | U1859 |
U1859 Suzuki Splash Symptoms
Check Engine Light
Illuminated Suzuki Splash dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Suzuki Splash
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Suzuki Splash
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 Suzuki Splash 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:
Crankshaft position sensor signals the computer for precise ignition and fuel injection timing. Faulty sensors cause rough running and reduced efficiency. Modern vehicles enter limp mode and illuminate the check-engine light.
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.
Suzuki Splash U1859 Repair Cost
Fuel injector cleaning service on the Suzuki Splash costs $150–$300 for an ultrasonic bench-clean of all injectors with flow-test certification. On-car induction cleaning is a cheaper ($80–$120) first step but is less thorough for heavily fouled injectors.
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 Suzuki Splash
Some Suzuki Splash 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 Suzuki Splash
The coolant temperature sensor on the Suzuki Splash 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 Suzuki Splash
For turbocharged Suzuki Splash models, allowing the engine to idle for 60–90 seconds before shutdown after hard driving reduces turbocharger heat soak and prevents the coking of oil that blocks VVT galleries — a known secondary trigger of U1859.
Frequently Asked Questions — Suzuki Splash U1859
A: U1859 is a standardised OBD-II code that can appear on any make and model. However, the specific components and circuits that trigger this code, and the repair procedures involved, vary significantly between vehicles. The information on this page is focused on the Suzuki Splash.