Wiring fault in the metering control circuit, such as open circuit, short to earth or high resistance; Corroded, loose or damaged connector at the pump or control unit; Faulty fuel metering valve or solenoid on the injection pump; Low or unstable supply voltage from a weak battery or poor earth; Internal injection pump fault, including a worn or sticking metering mechanism; Fuel supply problem such as restricted filter, air in the fuel or contamination affecting metering response; Faulty engine control unit driver circuit.

P0253

Injection Pump Fuel Metering Control A Low (Cam/Rotor/Injector).

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
2: AreaFuel and air metering (injector circuit)
53: FaultThe specific fault in that area

What it means

P0253 is the generic code for the injection pump fuel metering control 'A' circuit reading low on a diesel engine with a cam, rotor or injector type pump. The engine control unit commands a fuel quantity or metering position and sees the circuit voltage, current or feedback is lower than expected. The exact circuit and test limits depend on the engine and pump design.

Symptoms

Engine cranks but will not start, or is hard to start
Loss of power or limp mode
Rough running or uneven idle
Engine stalling or cutting out
Engine warning light on
Excess smoke or poor fuel economy

Possible causes

Wiring fault in the metering control circuit, such as open circuit, short to earth or high resistancelikely
Corroded, loose or damaged connector at the pump or control unitlikely
Faulty fuel metering valve or solenoid on the injection pumplikely
Low or unstable supply voltage from a weak battery or poor earthpossible
Internal injection pump fault, including a worn or sticking metering mechanismpossible
Fuel supply problem such as restricted filter, air in the fuel or contamination affecting metering responsepossible
Faulty engine control unit driver circuitrare

How to diagnose

Read all stored codes and freeze frame data to see engine speed, load and voltage when the fault set, and note any related codes
Check battery condition and charging voltage, and inspect main earth connections
Visually inspect the pump harness and connectors for chafing, heat damage, fluid ingress and corrosion
Check the fuel system basics: filter condition, fuel quality, leaks and air ingress on the supply side
Using live data, compare commanded and actual metering values, following the manufacturer procedure for the engine
Test the metering circuit for supply, earth, continuity and short circuits with the connectors disconnected, comparing against the manufacturer's specification
Measure the metering valve or solenoid resistance and compare it to the specification for that model
If wiring and the valve test fine, consider pump or control unit faults and confirm with manufacturer-specific tests

How to fix

Repair or replace damaged wiring and clean or renew faulty connectors
Replace the fuel metering valve or solenoid if it is out of specification
Correct battery, charging or earth faults
Replace the fuel filter, bleed the system and drain or replace contaminated fuel
Repair or replace the injection pump if internal faults are confirmed
Have the control unit checked or replaced only after the wiring and pump have been ruled out

Can I keep driving?

Medium severity

The car may run in limp mode or stall unexpectedly, so avoid driving it other than to get it checked soon. If it stalls or loses power, stop driving until it is repaired.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.