Fix P018B: Mechanic’s solutions that WORKED

The code P018B: Fuel Pressure Sensor B Circuit Range/Performance points out a fault in the Fuel Pressure Sensor B Circuit, suggesting a range or performance issue. This problem can stem from a defective sensor, issues within the fuel pump or its circuit, wiring, and connector problems, or communication errors in the vehicle’s control modules.

P018B quick overview

Description	P018B: Fuel Pressure Sensor B Circuit Range/Performance
Is it serious?	Yes, this code can be serious as it relates to the vehicle’s fuel system, which is crucial for engine performance and safety.
Possible causes	– Faulty fuel pressure sensor – Issues with the fuel pump or its circuit – Wiring or connector problems in the fuel system – Control module communication errors
How to diagnose?	Check Fuel Pressure Sensor: Inspect the sensor for faults or damage. Evaluate Fuel Pump: Assess the fuel pump’s condition and operation. Inspect Wiring and Connectors: Look for issues in the wiring or connectors related to the fuel system. Review Control Modules: Consider potential problems with modules like the PCM, especially in their communication with the fuel system.

How to fix P018B – learn from mechanics

I looked into P018B service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Ram

Vehicle Information: 2017 Ram 1500 Rebel 5.7L

Issue + Repair History:

• Initially set a P018C code for low fuel pressure circuit.
• After replacing the sensor and connector, it started setting a P018B code.
• Fuel pump replaced with an OEM unit, but the code persisted.
• Found 3.6v on the signal return wire at the sensor with it unplugged.
• Replaced the ECM, but the problem remained.

Other OBD2 Codes + Test Results:

• P018B – Fuel pressure range performance

Suggestions to Fix Issue:

• Check for high resistance or a resistive short to ground in the circuit.
• Consider rewiring the sensor to the 2022 diagram specifications.

Final Fix:

• Rewired the connector to the 2022 specs, resolving the issue. Signal, return, and ground pin locations differed between 2017 and 2022 models.

Case #2: Chevrolet

Vehicle Information: 2016 Chevrolet Tahoe LT 5.3L

Issue + Repair History:

• Codes: P2635, P018B, P0131, P0151.
• Fault occurred at idle with long-term fuel trim at -35.0 and high-pressure fuel at only 36 psi.
• Currently running fine; MIL lamp turned off during road test.
• High-pressure pump operating at 740 psi at idle with long-term fuel trim at -5.

Other OBD2 Codes + Test Results:

• P2635: Fuel pump flow performance
• P018B: Fuel pressure sensor performance
• P0131: Low voltage bank1, sensor1
• P0151: Low voltage bank2, sensor1

Suggestions to Fix Issue:

• Check if high-pressure pump is leaking internally.
• Refer to TSBs PIP5411 and PIP5507B, especially in high ambient temperatures.
• Consider wiring issues relating to the sensor and fuel pump module.
• Inspect for potential diesel contamination in gasoline.
• Evaluate low-side fuel pump and delivery to the high side.

Final Fix:

• Replaced the fuel sensor for the supply pump. No problems reported since then.

Case #3: Ford

Vehicle Information: 2013 Ford Escape SE 1.6L

Issue + Repair History:

• Code: P018B-00-6c for fuel rail pressure circuit B.
• Fuel rail pressure below minimum; replaced fuel rail pressure sensor and pigtail wire connector.
• Issue persisted with same code despite data reading above minimum.

Suggestions to Fix Issue:

• Check for high-pressure pump failure by comparing actual and desired readings.
• Inspect for circuit or sensor issues.
• Compare actual fuel pressure reading against the computer’s registered pressure.
• Consider potential PCM (Powertrain Control Module) faults.
• Check and clean ground connections, especially on the left strut tower.
• Focus on the low-pressure sensor in the fuel feed line.

Final Fix:

• Replaced the low-pressure sensor on the fuel line located behind #4 coil. Test drive for 48 miles showed no recurrence of the code.

Case #4: Jaguar

Vehicle Information: 2012 Jaguar XF Supercharged 5.0L

Issue + Repair History:

• Intermittent stalling, usually in parking lots after a restart, and sometimes won’t restart until a bit of waiting.
• In-tank pump replaced at dealer 9 months ago.
• Scoped high-pressure pumps with no irregular findings.

Other OBD2 Codes + Test Results:

• P0627: Fuel Pump A Control – Circuit/Open
• P018B: Fuel Pressure Sensor B – Circuit Range/Performance. Signal is invalid

Suggestions to Fix Issue:

• Consider updating software, referencing recalls on similar models.
• Check for burnt fuel tank connector or high resistance in the pump connector.
• Look into replacing the rear body harness or using a retrofit Land Rover harness (Part number: LR020971).

Final Fix:

• Replaced fuel tank/pump adapter unit due to a slightly burnt pin and installed the provided harness (Part number: LR020971). High-pressure pumps were also swapped. No codes have returned so far.

Case #5: Chevrolet

Vehicle Information: 2015 Chevrolet Silverado 1500 LT 5.3L

Issue + Repair History:

• SES light on without other symptoms.
• Codes: P2635, P018B, U0074, U18A2.
• Fuel pressure at 85.9 psi (desired 46.5 psi); gauge confirmed 85 psi.
• Fuel Enable and fuel pump command both at 0.
• Replaced fuel pressure sensor, fuel pump module, and fuel pump.

Other OBD2 Codes + Test Results:

• P2635: Fuel Pump Flow Performance
• P018B: Fuel Pressure Sensor Performance
• U0074: Control Module Communication Powertrain CAN Off
• U18A2: Lost Communication With Fuel Pump Module

Suggestions to Fix Issue:

• Check related TSBs for similar codes and high ambient temperature issues.
• Address U0074 code first due to its potential impact on P2635.
• Inspect the 20 pin connector near LF shock for communication issues.
• Check resistance across data lines between PCM and FPCM.

Final Fix:

• Replaced PCM after confirming circuitry between PCM and FPCM was fine and resistance readings were normal. Programming of the new PCM resolved all issues.

Common Advice for Solving Code P018B	Brief Description of Diagnostic Step
Check Fuel Pressure Sensor and Circuit	Inspect the fuel pressure sensor for faults and examine its circuit, including wiring and connectors.
Inspect Fuel Pump and Related Components	Evaluate the fuel pump’s functionality and condition, including checking for internal leaks or pressure issues.
Analyze Fuel System Data and Pressure	Use diagnostic tools to monitor fuel pressure data against desired values and confirm system integrity.
Review Related Technical Service Bulletins (TSBs)	Check for any TSBs that might provide guidance specific to the vehicle model concerning the P018B code.
Consider Control Module Issues	Examine the possibility of problems with control modules like the PCM (Powertrain Control Module), especially in communication with the fuel system.