Question 1

What does Mitsubishi fault code P0087 mean?

Accepted Answer

P0087 (Fuel System): Engine Stalls on Acceleration / Fuel Cut Fix: LOGIC: Fuel Rail Pressure Too Low (High Pressure System Drop).

ACTION: Replace primary fuel filter/water separator. Measure electric fuel pump supply volume. Inspect fuel tank pickup strainer for biological fuel slime / algae blockages.

Question 2

What does Mitsubishi fault code P0088 mean?

Accepted Answer

P0088: Engine "hunting" at idle; Loud fuel knock; Sudden limp mode; Common on 4D56 engines. Fix: Fuel Rail Pressure Too High.

LOGIC: The Suction Control Valve (SCV) is failing to regulate the fuel flow into the high-pressure pump, causing pressure spikes.

ACTION: 1. Inspect the SCV on the high-pressure pump. 
2. Check for fuel contamination. 
3. Perform SCV "Learning" via scanner.

FIX: Replace the Suction Control Valve (SCV).

Question 3

What does Mitsubishi fault code P0089 mean?

Accepted Answer

P0089 (Fuel Control): Surging Idle / Stalling on Deceleration Fix: LOGIC: Suction Control Valve (SCV) Performance / Fuel Pressure Regulator 1.

ACTION: Monitor target vs. actual common rail pressure on a scan tool at warm idle (spec: ~30–35 MPa). If actual pressure fluctuates >±5 MPa, replace the SCV and run the small-injection quantity learning.

Question 4

What does Mitsubishi fault code P0093 mean?

Accepted Answer

P0093: Engine stalls under load; Sudden loss of power; "Large Fuel Leak" warning. Fix: Fuel System Leak Detected - Large Leak.

LOGIC: The ECU sees a massive drop in rail pressure that doesn't align with commanded fuel delivery.

ACTION: 1. Check the Fuel Rail Pressure Relief Valve (PRV) for "weeping." 
2. Perform an injector leak-back test. 
3. Inspect high-pressure lines for cracks.

FIX: Replace leaking Injector or the Pressure Relief Valve on the fuel rail.

Question 5

What does Mitsubishi fault code P0102 mean?

Accepted Answer

P0102: Low power; Engine "suffocating" under load; Black smoke; Poor gear shifts (Auto). Fix: Mass Air Flow (MAF) Circuit Low.

LOGIC: Signal voltage is below 0.5V. This usually means the sensor is unplugged or the sensing element is extremely dirty/broken.

ACTION: 1. Inspect the MAF sensor connector for loose pins. 
2. Clean the sensor using dedicated MAF cleaner only. 
3. Check for 12V and 5V power at the plug.

FIX: Clean or replace the MAF Sensor; repair broken ground wire in the harness.

Question 6

What does Mitsubishi fault code P0193 mean?

Accepted Answer

P0193 (Fuel System): Loud Engine Knock / Rail Pressure Alarm Fix: LOGIC: Fuel Rail Pressure Sensor Circuit High (Open Ground).

ACTION: Check continuity of the sensor ground circuit back to the Denso ECU. Measure signal pin voltage with key on, engine off (spec: 0.5V; an open ground causes a 5.0V reading).

Question 7

What does Mitsubishi fault code P0299 mean?

Accepted Answer

P0299: "Lazy" acceleration; Turbo won't "spool" up; Underboost code. Fix: Turbocharger Underboost Condition.

LOGIC: Actual manifold pressure is lower than the target pressure commanded by the ECU.

ACTION: 1. Inspect all intercooler hoses for splits. 
2. Check the VGT solenoid vacuum lines. 
3. Verify the VGT actuator moves freely.

FIX: Replace split intercooler hoses; replace VGT vacuum solenoid; replace Turbocharger.

Question 8

What does Mitsubishi fault code P0299 mean?

Accepted Answer

P0299 (Induction / Turbo): Severe Turbo Lag / Power Loss Climbing Grades Fix: LOGIC: Turbocharger Underboost Condition.

ACTION: Check the Variable Geometry Turbo (VGT) vacuum actuator and electronic boost solenoid. Verify smooth mechanical movement of the internal VGT nozzle ring vane linkage without binding.

Question 9

What does Mitsubishi fault code P0403 / P0405 mean?

Accepted Answer

P0403 / P0405: Rough idle; "Check Engine" and "VSC" lights; Engine surging. Fix: EGR Volume Control Circuit / Position Sensor Low.

LOGIC: The ECU detects an electrical fault in the EGR motor winding or the position sensor signal is out of range.

ACTION: 1. Unplug EGR motor; check for corrosion in pins. 
2. Check resistance of motor windings. 
3. Check for carbon buildup jamming the valve open.

FIX: Replace the EGR Valve assembly or repair the harness connector.

Question 10

What does Mitsubishi fault code P0500 mean?

Accepted Answer

P0500 (VSS): Speedo Inop / Erratic Idling Fix: LOGIC: Vehicle Speed Sensor Malfunction.

ACTION: Check the speedo cable (if mechanical) or the VSS sensor on the tail-shaft.

Code	System	Symptom	Full fix
P0087	Fuel System	Engine Stalls on Acceleration / Fuel Cut	View fix
P0088	—	Engine "hunting" at idle; Loud fuel knock; Sudden limp mode; Common on 4D56 engines.	View fix
P0089	Fuel Control	Surging Idle / Stalling on Deceleration	View fix
P0093	—	Engine stalls under load; Sudden loss of power; "Large Fuel Leak" warning.	View fix
P0102	—	Low power; Engine "suffocating" under load; Black smoke; Poor gear shifts (Auto).	View fix
P0193	Fuel System	Loud Engine Knock / Rail Pressure Alarm	View fix
P0299	—	"Lazy" acceleration; Turbo won't "spool" up; Underboost code.	View fix
P0299	Induction / Turbo	Severe Turbo Lag / Power Loss Climbing Grades	View fix
P0403 / P0405	—	Rough idle; "Check Engine" and "VSC" lights; Engine surging.	View fix
P0500	VSS	Speedo Inop / Erratic Idling	View fix
P0502	—	Speedometer reads zero; "ABS" light on; Transmission won't shift out of 1st gear.	View fix
P0638	—	Sudden loss of throttle; Engine stuck at high idle (Limp Mode); Throttle icon on dash.	View fix
P1298	Air Intake / Turbo	Black Smoke / Heavy Turbo Lag	View fix
P1298	—	Engine overheats; AC stops working; Fan won't engage.	View fix
P1496	Emissions / EGR	EGR Warning / Limp Mode Active	View fix
P2413	—	Frequent DPF warning; Excessive fuel consumption; Power derate.	View fix
P2452	—	DPF light flashing; Constant regens; Limp mode.	View fix
P2454	Emissions / DPF	DPF Light Flashing / Check Engine	View fix

Mitsubishi Fault Codes

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