P027E — Cold Start Fuel Injection Quantity A Lower Than Expected

Diagnostic algorithm

1. Retrieve DTC, freeze frame and related codes; record live data during a cold start attempt
2. Confirm test conditions replicate ‘cold start’ thresholds (engine and ambient temps per freeze frame) before retest
3. Visually inspect wiring and connectors for injectors, fuel pump, fuel pressure sensor and relevant sensors (MAF, IAT). Repair any damage or poor connections
4. Measure fuel rail pressure during cranking and first seconds after start; compare to manufacturer spec. If low, inspect filter, pump, pressure regulator and supply lines
5. Compare commanded injector pulse width to measured injector flow (if available) or use a noid light/oscilloscope to verify injector driver pulses and coil waveform
6. If injectors are suspected, perform flow test or balance test (lab or on-vehicle) to identify restricted or low-flow injector(s); clean or replace as required
7. Check MAF/IAT and other air metering sensors for correct output and response; clean or replace MAF if contaminated
8. Check fuel temperature sensor and fuel composition compensation inputs; confirm PCM has proper calibrations and no TSB/software update applies
9. If electrical fault suspected, check PCM power and ground integrity and battery condition; repair as necessary
10. Clear codes and perform controlled cold-start test to verify repair. If intermittent, consider logging during multiple cold starts or using an oscilloscope/data logger for longer capture