Volvo FH12 User Manual

Volvo FH12 with engine D12A - fault codes

Code

Description

Cause and reaction.

11

Accelerator pedal
sensor.

Accelerator pedal sensor is defective or damaged wiring between the

motor control unit and foot pedal. Incomplete pressing the accelerator

pedal may have a sharp increase in engine speed.

12

Idling speed
switch pedal.

Accelerator pedal sensor is defective or damaged wiring between the

motor control unit and foot pedal. The accelerator pedal is not

responding to pressing.

13

Vehicle speed
signal.

Damaged wiring, faulty dash, faulty Tachograph. Cruise control does not

work until the fault code is active.

14

Power relay
engine control
unit.

The relay is defective or damaged wiring.

21

Internal
malfunction of the
engine control
unit.

Defective engine control unit. Cruise control does not work.

22

A programming
error in the engine
control unit.

Not programmed or programmed with a buggy engine control

unit. Engine will not start.

23

Coolant
temperature
sensor.

The sensor may be faulty, damaged wiring, water pump works with

incomplete effectiveness, crammed with honeycomb radiator or

defective thermostat.

24

Charge air
temperature.

The sensor may be faulty, damaged wiring, clogged honeycomb

intercooler (an intercooler), mechanical failure of the engine. At

temperatures above 91° air discharge with "Check Engine" lamp will

light up continuously when the engine power will be reduced. In the

event of a fault in the wiring harness or defective sensor "Check Engine"

lamp will blink.

25

Charge air
pressure.

The sensor may be faulty, damaged wiring, defective, damaged or

clogged the turbocharger intercooler cooler, mechanical failure of the
engine.Reduced engine power increased the toxicity of exhaust gases.

26

Speed sensor
camshaft.

Faulty speed sensor camshaft, damaged wiring, broken synchronization

between signals from speed sensor camshaft and crankshaft sensor. In

case of violation of synchronization will be active codes 26 and 27 at

the same time.Engine runs for a long time or may not start for the first

time.

27

Speed sensor the
crankshaft.

Faulty speed sensor, crankshaft damaged wiring, broken synchronization

between signals from speed sensor camshaft and crankshaft sensor. In

case of violation of synchronization will be active codes 26 and 27 at

the same time.Engine runs for a long time or may not start for the first

time.

31

Pump-injector
cylinder No. 1.

Defective pump-injector, damaged wiring between the motor and the

control unit pump-injector, mechanical failure in the engine. Engine is

not exactly possible increased exhaust gas smokiness.

32

Pump-injector
cylinder No. 2.

Defective pump-injector, damaged wiring between the motor and the

control unit pump-injector, mechanical failure in the engine. Engine is

not exactly possible increased exhaust gas smokiness.