Subaru Legacy 2004 Service Manual page 898

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
10 CHECK MANIFOLD PRESSURE SENSOR
SIGNAL.
1) Start and warm-up the engine until engine
coolant temperature is above 60#C (140#F).
2) Place the select lever in "N" or "P" position.
3) Turn the A/C switch to OFF.
4) Turn all accessory switches to OFF.
5) Read the data of manifold pressure sensor
signal using Subaru Select Monitor.
NOTE:
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4SO 2.5)(diag)-26, Subaru Select Mon-
itor.>
Check
Is the measurement value 24.0
— 41.3 kPa (180 — 310
mmHg, 7.09 — 12.20 inHg)
when idling and 73.3 — 106.6
kPa (550 — 800 mmHg, 21.65
— 31.50 inHg) when the igni-
tion turns to ON?
EN(H4SO 2.5)(diag)-139
ENGINE (DIAGNOSTICS)
Yes
Replace the ECM. Replace the mani-
<Ref. to FU(H4SO fold pressure sen-
2.5)-36, Engine sor. <Ref. to
Control Module FU(H4SO 2.5)-25,
(ECM).> Manifold Absolute
Pressure Sensor.>
No