Code
P1653
DAEWOO
P — Powertrain
Fuel cut flt after eng off
Views:
UK: 3
EN: 13
RU: 4
AI status
Completed
Completed
100%
Causes
- Faulty fuel pump relay (stuck closed or welded contacts)
- Short or open in fuel pump/relay control wiring
- Faulty fuel pump control module or fuel pump driver
- Defective ECM (incorrect control or monitoring of fuel cut)
- Ignition switch or ignition circuit not signalling engine-off
- Poor ground or power supply to ECM or relay coil
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated
- DTC P1653 stored in engine control module
- Engine may continue to run/rundown after key-off or may be hard to shut off
- Fuel smell after engine is turned off
- Battery drain after shutdown (parasitic draw)
- Difficulty restarting the engine or unintended cranking behavior
What to check
- Read and record trouble codes and freeze-frame data with a suitable scan tool
- Perform key-on/key-off and engine-off cycles while monitoring live data for fuel pump relay control and fuel rail pressure
- Visually inspect fuel pump relay, fuses and relay socket for corrosion, heat damage or welded contacts
- Check for voltage at the fuel pump relay coil/control pin with ignition on and off
- Measure fuel pump current draw with a suitable ammeter to detect stuck-on pump
- Check continuity and insulation of wiring between ECM, relay and fuel pump
Signal parameters
- Fuel pump relay control voltage: ~12 V when commanded on, ~0 V (or open) when off
- Fuel pump current draw: >0 A when running, ≈0 A within seconds after key-off
- Fuel rail pressure: normal operating pressure when engine runs; should fall toward 0–ambient after shutoff
- Injector drive: no injector pulse after ignition off
- Battery voltage: steady ~12–14 V with ignition on; no unexpected voltage when off
- ECM ground resistance: low (typically
Diagnostic algorithm
- Retrieve and record stored codes and freeze-frame; clear codes and attempt to reproduce to confirm P1653 returns.
- With a scan tool, monitor fuel pump relay command and fuel rail pressure during a controlled key-on/key-off and engine start/stop cycle. Note any mismatch between command and actual state.
- Inspect fuel pump relay and associated fuses. Swap with a known-good identical relay (if available) and retest.
- Measure voltage at the relay coil/control terminal with ignition on and off. Verify the control wire goes low/open when engine is off.
- Measure continuity and resistance between the ECM fuel control output and the relay coil. Repair any open or short circuits.
- Measure fuel pump current during and after shutoff. If the pump continues to draw current after shutoff, suspect a stuck relay, failed pump, or shorted control circuit.
- Inspect and test the ignition switch and any engine-off/ignition-off inputs to the ECM. Verify the ECM receives a correct engine-off signal.
- Check ECM power and ground circuits for corrosion, loose connections, or high resistance. Repair as needed.
- If wiring, relays, fuses and external modules test good, check for immobiliser or module conflicts that could affect fuel cut. Relearn or reset per factory procedure if required.
- If all external components and wiring are good, consider ECM diagnostics or replacement as a last step following manufacturer service information.
- Safety note: take fuel-system precautions when testing (no open flames, proper ventilation). Disconnect the battery before major electrical repairs.
Likely causes
- Fuel pump relay welded contacts causing permanent feed after shutoff
- Open/shorted control wire between ECM and fuel pump relay coil
- Blown or intermittent fuse in fuel pump/relay feed
- ECM not receiving ignition-off input due to ignition switch fault
- Fuel pump control transistor/module failure
Fault status
Status
ECM detected that fuel supply/control did not switch to the expected 'off' condition after engine/ignition off. The fault is stored when the monitored fuel control signal/state or fuel pressure/current is inconsistent with an engine-off condition.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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