Diagnostic trouble code (DTC) information ECM-91B7

Condition

Fig 1: Identifying Electronic Throttle Module (ETM)

Courtesy of VOLVO CARS OF NORTH AMERICA.

Every time the ignition is turned on, the Electronic throttle module (ETM) checks that the throttle disc is in its mechanical rest position. It is the same position that is used when Electronic throttle module (ETM), due to a fault, decides to turn off the control, that is approx. 20% throttle opening. If Electronic throttle module (ETM) registers that any of the two throttle position sensors' values are outside expected range, when the ignition is turned on, this information is sent to Engine control module (ECM), which then stores diagnostic trouble code ECM-91B7, Faulty position.

For upgraded software, released during year 2006 or later, the expected range is slightly larger and requires that both throttle position sensors are outside this range.

See Identifying upgraded software ECM/ETM

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:Design

See Function

Substitute Value

Closing of throttle during braking.

The accelerator pedal position is ignored when the brake pedal is depressed.

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.

For upgraded software, released in 2006 or later, adjustments have been made to substitute values. For this fault, no replacement values will be activated.

See Identifying upgraded software ECM/ETM

Possible Source

the power supply to the throttle unit
poorly charged battery or corroded in the connecting cables
Damaged electronic throttle module (ETM).

This diagnostic trouble code is generated in combination with other trouble codes. Information on the possible root cause is described.
See Information about combined diagnostic trouble codes (DTCs)

Fault symptom[s]

the accelerator pedal (AP) is ignored when braking
the cruise control cannot be activated
the ETS warning lamp lights (C70 and S/V70 -2000 only).