Diagnostic trouble code (DTC) information

Condition

Fig 1: Identifying Brake Pedal Position Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

S60/V70 (00-)/V70 XC (01-)/S80 (-06)

Model year 1999-2001.

If Engine control module (ECM) registers that the signal from the brake pedal position sensor is:

Lower than 9.0 % (0.45 V) for longer time than 0.16 seconds, then ECM-9400, Too low signal, is stored.
Higher than 83.2% (4.2 V) for longer than 0.16 seconds, then ECM-9400, Too high signal, is stored.
Between 73.1 % (3.7 V) and 83.2 % (4.2 V) for longer time than 0.16 seconds, then ECM-9400, Faulty signal, is stored.

Diagnostic trouble code ECM-9400, No signal, is generated if the engine control module (ECM) detects that the brake light switch is not closed even though the brake pedal is depressed. The trouble code is generated if the brake pedal position sensor indicates a value lower than 23.8% (1.2 V) for more than 0.16 seconds.

For upgraded software, released during year 2006 or later, the fault type Faulty signal is no longer necessary and therefore has been removed.With regards to detection times for other problem types, these are increased from 0.16 to 2 seconds.

Further adjustments have been performed with regards to the problem type Signal missing.If Engine control module (ECM) registers that:

The brake light switch is not closed even though the brake pedal is depressed. This is indicated by the brake pedal position sensor indicating a value less than 53.9% (2.7 V). This fault type is stored if this is repeated 30 times in a row.
The brake light switch is closed even though the brake pedal is released. This is indicated by the brake pedal position sensor indicating an adapted value less than 2.7% (0.14 V). This fault type is stored if this is repeated 30 times in a row.

For this test an adapted brake pedal position sensor value is used, that is, the control module adapts the signal so that it always shows 0 % (0 V) at released pedal, which is different from other tests where the direct signal from the sensor is used. Identifying upgraded software ECM/ETM

S70/C70/V70 (-00)/V70 XC

If Engine control module (ECM) registers that the signal from the brake pedal position sensor is:

Lower than 9.0 % (0.45 V) for longer time than 0.16 seconds, then ECM-9400, Too low signal, is stored.
Higher than 83.2% (4.2 V) for longer than 0.16 seconds, then ECM-9400, Too high signal, is stored.
Between 73.1 % (3.7 V) and 83.2 % (4.2 V) for longer time than 0.16 seconds, then ECM-9400, Faulty signal, is stored.

If Engine control module (ECM) registers that the brake light switch is not closed, despite the brake pedal being pressed down, which is indicated by the brake pedal position sensor showing lower value than 32.8 % (1.6 V), for longer time than 0.16 seconds, then diagnostic trouble code ECM-941F, Signal missing, is stored.

Further adjustments have been performed with regards to the problem type Signal missing.If Engine control module (ECM) registers that:

The brake light switch is not closed even though the brake pedal is depressed. This is indicated by the brake pedal position sensor indicating a value less than 55.9% (2.8 V). This fault type is stored if this is repeated 30 times in a row.
The brake light switch is closed even though the brake pedal is released. This is indicated by the brake pedal position sensor indicating an adapted value less than 2.7% (0.14 V). This fault type is stored if this is repeated 30 times in a row.

For more information about the electronic throttle system and related components such as the electronic throttle module, accelerator pedal position sensor, brake light switch, clutch pedal position sensor, and brake pedal position sensor:

See Design
See Function

Substitute Value

Cruise control off.

Cruise control off during entire operating cycle in which fault was detected.If the fault is no longer present, the function is available the next time the car is started.

Possible Source

Signal too high

short-circuit to supply voltage in the signal cable
Open-circuit in brake pedal sensor signal cable
open-circuit in brake pedal sensor ground lead
defective brake pedal position sensor.

Signal too low

signal cable from brake pedal sensor short-circuited
short-circuit to ground in the signal cable
defective brake pedal position sensor.

Signal missing

Open-circuit in stop (brake) light switch signal cable
defective brake pedal position sensor.

Faulty signal

incorrectly installed brake pedal sensor
defective brake pedal position sensor.

Fault symptom[s]

general orange warning lamp lit
cruise control shut off