SAAB WIS ONLINE

P0502

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE. Cruise control inoperative. Low engine torque on cars with manual gearbox.

P0502


Vehicle Speed. No input signal.



Fault symptoms


• CHECK ENGINE.

• Cruise control inoperative.

• Low engine torque on cars with manual gearbox.


On-Board Diagnostics

Type of diagnosis:


- Continuous. But interrupted when fault criteria fulfilled and will not restart until next driving cycle.


Enable criteria:


- Engine running. Engine speed above 1750 rpm. Load above 480 mg/c. Brake pedal not depressed. Coolant temperature above 60°C.


Fault criteria:


- No vehicle speed for more than 5 s.

Then, 17 minutes without the vehicle speed leaving 0. On automatic cars, the selector lever must also have another value than P or N. Enable criteria for these two fault criteria need not be fulfilled.


Dependents:


- P1576 and P1577.


System reaction to a fault:


- Cruise control is blocked. Vehicle speed (Bus from MIU) is used as a substitute value. The idling adaptation is blocked and reset.


OK report:


- 60 s has expired since start. Vehicle speed has exceeded 0 on some occasion.


Fault handling: (See section Fault handling III, other emission-related components and functions for more information.)


- Type III.


Diagnostic help

Fault diagnosis concerns electrical faults in connecting cables to ESP. Communication with Trionic is on the P-bus. For further information on bus communication with ESP, see Fault diagnosis strategy for electronic systems . If ESP is missing from the bus, DTC P1625 will be generated, see P1625 .

Functions in the diagnostic tool related to the fault:


• Diagnostic status for the diagnosis.

• Vehicle speed (Lead from ABS, alternatively bus from TC/ABS), unit km/h.


See also description of read value under "Read Values" menu for more information.

Checking the wiring

Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Observe the multimeter, diagnostic tool or test lamp during the check.