Saab 9000 - Page 135

132 Fault diagnosis
Diagnostic trouble code P0141
Heating, rear heated oxygen sensor
Symptom of fault
The CHECK ENGINE lamp (MIL) is on.
Conditions
•
Heat~ng
circuit
active
• Heating circuit current below 500 mA or above
2300 mA for 5 seconds.
Note
Oxygen sensor heating is activated at engine coolant
temperatures above
so
0
c
(122°F).
µp
µp
H70-1
47
70 67
51
Diagnostic help
The oxygen sensor
1
s heating circuit current can be
ascertained using an ISAT scan tool.
- Select "READ FUNCTIONS".
- Select "O2S 2 PREHEATING"
With the engine hot, the ISAT scan tool should show
a heating current of 700-1000 mA.
Oxygen sensor heating can be activated by means
of the ISAT scan tool.
- Select "ACTIVATE".
- Select "O2S 2".
If diagnostic trouble codes P0135 and P0141 are
present, the cause of the fault is:
- because fuse 28 has blown
- the common power supply for the oxygen sen-
sors from fuse 28 is absent
Saab 9000