P0327

Symptom: The car is running on basic charging pressure only, continuous ignition retardation.

P0327

Fault symptoms

The car is running on basic charging pressure only, continuous ignition retardation.

Note

Saab Trionic does not have a conventional knock sensor. The signal comes from the ignition discharge module.

Conditions

•	Engine running

•	Knock signal absent for 10 sec.

Diagnostic help

The knock signal can be read with the diagnostic tool.

-	Select " Data Display / Output Control (New)".

-	Select " Knock Sensor".

the diagnostic tool should show between 0 and 2.55 V depending on the level of the knock signal.

The diagnostic tool should show 0.06 - 0.16 V at idling speed and can show 0.06 - 2.55 V during fast acceleration.

Normally, 0.06 - 0.08 V is shown if there is a break in the signal lead to control module pin 44, irrespective of acceleration.

Checking the wiring harness. Intermittent faults may occur in connection with short circuits and open circuits. Jiggle the wiring harness at several points and in several directions to locate any problems in the wiring, including intermediate connectors. Observe the multimeter, scan tool or test lamp during the check.