Code
P1110
DAEWOO
P — Powertrain
FUEL PUMP - STUCK
Views:
UK: 2
EN: 5
RU: 5
AI status
Completed
Completed
100%
Causes
- Fuel pump mechanical seizure or internal hydraulic blockage (contamination, varnish)
- Fuel pump electrical short causing pump to be held on
- Stuck or welded pump relay or relay contacts
- Failed fuel pump control module or PCM output circuit
- Clogged fuel filter or restriction causing abnormal pump loading
- Wiring harness damage, chafing or connector corrosion at pump
Symptoms
- Check Engine Light (MIL) illuminated with P1110 stored
- Engine cranks but does not start, or starts intermittently
- Low or no fuel pressure at rail
- Engine stalls or loses power under load
- Fuel pump runs continuously (key off) or does not prime when key is turned on
- Unusual fuel pump noise (grinding, whining)
What to check
- Scan for stored/related codes and freeze-frame data
- Listen for fuel pump priming with key ON (tank-level noise)
- Check fuel pump fuse and relay operation; swap relay with known-good if available
- Visually inspect fuel pump wiring and connector for corrosion, damage or pinched wires
- Measure voltage at pump connector with key ON and during cranking (use back-probing)
- Measure fuel pump current draw with clamp meter or ammeter to detect excessive or zero draw
Signal parameters
- Key-ON supply voltage at pump: approximately battery voltage (about 11–14 V) — should be present during priming and cranking
- Pump current draw (typical in-line pump): commonly in the range of a few amps to ~10 A depending on pump — look for sudden high or zero readings
- Fuel rail/static pressure: typically ~30–60 psi (2–4 bar) for many gasoline systems — verify against vehicle spec
- Fuel pressure during cranking and under load: pressure should rise to spec quickly and hold; large drops or inability to reach spec indicate pump/problem
- If PWM controlled: pump duty cycle and frequency from PCM should change with engine load — compare to known-good waveform
Diagnostic algorithm
- Read and record all codes and freeze-frame data. Check for related codes (fuel pressure/sensor, pump circuit).
- Visually inspect fuses, pump relay, wiring and connectors for obvious damage or corrosion.
- Safety: relieve fuel system pressure and disconnect battery when accessing fuel system components.
- Check for pump prime noise with an assistant turning key to ON; if no noise, verify fuse/relay and back-probe pump connector for battery voltage with key ON and during crank.
- If voltage present but pump does not run, measure pump current draw — no current suggests open circuit or bad pump; very high current suggests mechanical binding or shorted pump.
- If pump runs but pressure low, perform fuel pressure test at rail (static and during cranking/load). Replace fuel filter if clogged and re-test.
- If pump is suspected mechanical or contaminated, lower fuel tank and remove pump module for bench test (observe rotor rotation, current draw and flow).
- If electrical issue suspected, check continuity and resistance of wiring to PCM and ground integrity. Inspect for shorts to ground that could force pump on or off.
- If PCM or pump control module outputs look abnormal (no drive or stuck-on PWM), confirm with oscilloscope and compare to expected waveforms; consider replacing module only after verifying wiring and relay.
- Clear codes and perform road test after repair. Re-scan and verify code does not return.
- Document findings and replace faulty components as required (relay, pump module, filter, wiring, PCM) — do not replace PCM/MCM until all lower‑level causes are ruled out.
Likely causes
- Faulty or sticking fuel pump relay or relay contacts
- Contaminated or seized in-tank fuel pump (wear, debris, corrosion)
- Wiring/connector fault to pump (short to ground or high resistance)
- Faulty pump control output from PCM or fuel pump module
Fault status
Status
Fuel pump stuck condition detected. PCM observed abnormal pump behavior (stuck on, not cycling, excessive load or no response). Investigate pump, relay, wiring and pump control circuitry.
Repair difficulty: Medium
Diagnostic time: 1.0 - 3.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email