Code
P1108
FIAT
P — Powertrain
Electric fan assembly 1 fault
Views:
UK: 6
EN: 9
RU: 7
AI status
Completed
Completed
100%
Causes
- Blown fuse or faulty main fuse link for fan circuit
- Faulty fan motor (electrical or mechanical failure)
- Bad fan relay or fan driver module (internal to fan assembly or separate)
- Open, shorted, corroded or damaged wiring and/or connectors between ECM/PCM and fan
- Poor ground or grounding strap failure
- ECM/PCM output driver fault or software issue
Symptoms
- Check Engine / MIL illuminated
- Cooling fan 1 does not run when commanded (engine hot or A/C on)
- Intermittent fan operation
- Engine running hotter than normal or higher idle temperature
- Reduced A/C performance at low vehicle speed
- Unusual noise from fan area (bearing or blade contact)
What to check
- Read stored freeze frame and live data with a scan tool; re-run readiness and monitor fan command and actual fan status
- Visual inspection of fan, wiring harness, connectors and grounds for corrosion, damage or contamination
- Check relevant fuses and relays for continuity and correct seating
- Perform a functional command test (command fan ON via scan tool) and observe operation
- Measure supply voltage at fan connector with fan commanded ON (should be near battery voltage)
- Measure continuity and resistance of fan motor and wiring to chassis ground
Signal parameters
- Command voltage: when commanded ON the fan circuit should present near battery voltage at the motor supply terminal (approx. battery V)
- Control signal: some systems use PWM; expected duty cycle varies 0–100% and frequency typically in the tens to hundreds of Hz
- Motor resistance: low ohms (motor coil); an open circuit indicates failed motor
- Current draw: typical electric radiator fans often draw several amps up to tens of amps; excessive current indicates seized/worn motor or short
- Ground continuity: low resistance to chassis ground from fan ground terminal
Diagnostic algorithm
- Retrieve codes and live data; note freeze frame, ambient & coolant temperatures, and whether A/C was requested.
- Visually inspect fan assembly, shroud, connector and wiring for obvious damage, corrosion or loose pins.
- Check fuses and relays related to fan circuit; replace suspect items and retest.
- Using a scan tool, command the fan ON. If fan runs, monitor voltage and current; if not, proceed to direct tests.
- With ignition off, disconnect fan connector and measure resistance of the fan motor. An open or infinite reading indicates a bad motor.
- With connector disconnected, check for battery voltage at the supply terminal when fan is commanded ON to verify power feed and relay/driver function.
- Check ground continuity from fan ground terminal to chassis. Repair poor grounds as needed.
- If power and ground are present and motor is within specs but does not run, bench-test or replace the fan motor/assembly.
- If motor is OK but control signal is absent or erratic, test relay, fan driver module and ECM output; consult wiring diagram and test components per manufacturer procedures.
- After repair, clear codes, perform functional tests and road/idle test to ensure proper fan operation and that code does not return.
Likely causes
- Corroded/loose fan connector or ground (very common)
- Failed fan motor (high current draw or open circuit)
- Blown fuse or failed relay
- Faulty fan control module/driver
- Damaged wire (short to power or ground) on the fan power/control circuit
Fault status
Status
Electric fan assembly 1 fault — ECM/PCM detected abnormal condition in cooling fan 1 circuit (open/short/high current/no response/driver failure). Inspection of fan motor, wiring, connectors, fuses, relays and driver required.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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