Code
P1624
DAEWOO
P — Powertrain
Radiator fan mal
Views:
UK: 4
EN: 5
RU: 5
AI status
Completed
Completed
100%
Causes
- Blown fuse or faulty fan relay
- Faulty radiator fan motor
- Open/short in fan wiring or poor ground
- Faulty fan control module or ECU output
- Incorrect coolant temperature sensor input
- Corroded/loose connector or mechanical obstruction
Symptoms
- Cooling fan does not run when engine is hot or when A/C is on
- Cooling fan runs continuously or at incorrect speed
- Engine overheating or temperature fluctuates high
- Reduced air conditioning performance at low speeds/idle
- Check engine light or warning lamp illuminated
- Unusual fan noise or grinding if motor bearings are bad
What to check
- Read DTCs and freeze frame data with a scan tool; note coolant temp and fan command status
- Visually inspect fan, shroud, connector and wiring for damage or corrosion
- Check cooling fan fuse(s) and relay(s); swap relay with known good one if applicable
- Command fan ON/OFF with a scan tool and observe operation
- Measure battery voltage at fan connector while commanding fan on
- Check continuity to ground and measure resistance of fan motor
Signal parameters
- Supply voltage at fan connector: approx. 11–14.5 V with engine running
- Motor current draw: typically several amps (commonly 5–25 A depending on fan); abnormally high indicates seized or damaged motor
- Motor resistance (DC): low ohm range (varies by design); an open circuit indicates motor/connector fault
- Control signal: either switched 12 V or PWM duty cycle (0–100%) from ECU; frequency commonly tens to a few hundred Hz on PWM systems
- Ground continuity: near 0 Ω between fan ground pin and chassis ground
- Fan-on temperature threshold: typically when coolant reaches specified temperature (often ~85–105 °C) or when A/C refrigerant pressure requires cooling
Diagnostic algorithm
- Connect scan tool, record DTCs and freeze frame, and attempt to command fan ON; note whether ECU issues a command.
- If ECU commands fan but it does not run, inspect fuses and relays related to fan circuit; replace if faulty.
- With fan command active, measure voltage at fan power pin and at fan ground; if no power, trace wiring to relay/ECU.
- If voltage present but fan does not spin, disconnect connector and bench test motor directly from battery to verify operation and current draw.
- If motor runs when directly powered, check relay operation and ECU/fan-controller output (measure PWM or switched voltage at connector).
- If no control signal from ECU, check continuity back to module and inspect for damaged wiring or connectors; consider ECU/fan module fault if wiring ok.
- If fan runs but intermittently or draws excessive current, replace fan assembly or motor bearings as required.
- Verify coolant temperature sensor readings with scan tool and compare to actual temp; replace ECT if giving false values causing incorrect fan control.
- Repair or replace failed components, clear DTCs and retest vehicle in relevant conditions (idle, A/C on, driving) to confirm repair.
Likely causes
- Blown fuse for cooling fan circuit
- Stuck or failed fan relay (no coil actuation or contacts open)
- Failed fan motor (no rotation or excessive current draw)
- Broken wire, rodent damage or pinched harness to fan
- High resistance or missing ground at fan motor
- Faulty radiator fan control module or ECU driver transistor
Fault status
Status
Radiator fan malfunction detected — cooling fan failed to operate or cooling fan control circuit fault. May cause overheating or reduced A/C performance.
Repair difficulty: Medium
Diagnostic time: 0.5-3.0 hours
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