DTC 5-1-4 Engine Cooling Fan Low Speed Signal

5-1-4 ENGINE COOLING FAN HALF SPEED, SIGNAL

Preconditions for DTC
^ If the engine cooling fan's signal lead is short circuited to ground/voltage or if there is a break in the circuit, the ECM interprets this as a fault and DTC 5-1-4 is set.

Substitute value
^ Idle air trim is inhibited.
^ Fuel trim is inhibited.
^ Conditions for fuel shut-off changed.
^ If engine coolant temperature exceeds 1O2°C (216°F) the engine cooling fan starts operating at full speed.

Fault sources
^ Signal too high:
- Signal lead short circuited to voltage supply.
- Defective Fan Control (FC) relay.

^ Signal too low:
- Signal lead, half speed short circuited to ground.
- Signal lead, full speed short circuited to ground.
- Break in signal lead.
- Break in voltage lead to engine cooling fan.
- Contact resistance in connectors.
- Defective FC relay.

Fault symptoms
^ May result in poorer performance.