What Does P1355 Mean?
P1355 indicates an intermittent signal from the fuel level sensor B or a malfunction in the bypass line monitoring circuit. On vehicles with dual fuel tank senders, sensor B is the secondary level sensor. An intermittent signal causes erratic fuel gauge readings. On some diesel applications, this code relates to the fuel system bypass line monitor, which tracks fuel return flow to detect injection system problems.
Common Causes
30%
Worn or corroded fuel level sensor B float arm contacts
25%
Loose or corroded wiring connector at the fuel tank sender unit
20%
Damaged wiring harness between the fuel tank and ECU/instrument cluster
15%
Fuel tank sender unit ground corrosion
10%
Failed fuel level sensor B requiring replacement
Diagnostic Steps
1
Monitor the fuel level sensor B signal with a scan tool while the vehicle is stationary. An intermittent sensor will show erratic voltage fluctuations rather than a steady reading.
2
Inspect the fuel tank sender electrical connector for corrosion, fuel contamination, or loose terminal pins. Clean and reseat the connector.
3
Check the wiring harness from the fuel tank to the ECU for damage, especially where it routes under the vehicle and is exposed to road debris and moisture.
4
Measure the fuel level sensor B resistance with the sender disconnected. Move the float arm through its full range and verify smooth, linear resistance change with no dead spots or dropouts.
5
If the sensor has dead spots or erratic resistance, replace the fuel tank sender assembly. Many modern vehicles integrate both sensor A and B into a single in-tank module.
Estimated Repair Cost
$100 - $500
Parts + labor, varies by vehicle and location
P1355 indicates an intermittent signal from the fuel level sensor B or a malfunction in the bypass line monitoring circuit. On vehicles with dual fuel tank senders, sensor B is the secondary level sensor. An intermittent signal causes erratic fuel gauge readings. On some diesel applications, this co...
The most common cause of P1355 (Fuel Level Sensor B Intermittent/Bypass Line Monitor) is: Worn or corroded fuel level sensor B float arm contacts
Typical repair costs for P1355 range from $100 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
An intermittent fuel level sensor can cause inaccurate fuel gauge readings, potentially leading to an unexpected empty tank situation. While not mechanically dangerous, running out of fuel creates a stranding hazard and on diesel engines can introduce air into the injection system.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1355 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel System / Instrumentation
Difficulty
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