2005 Saab 9-2X Aero ECU

ECU connector pinout for the 2005 Saab 9-2X Aero, a rebadged Subaru Impreza WRX sharing the H4DOTC 2.0 L turbo engine harness and five ECM connectors.

Updated:

ECU - Electronic Control Unit Connector ECU - Electronic Control Unit Connector.

The 2005 Saab 9-2X Aero is a US-market rebadge of the Subaru Impreza WRX and shares the same Fuji Heavy Industries H4DOTC 2.0 L horizontally-opposed turbocharged four-cylinder engine and engine harness. The Engine Control Module (ECM) uses five connectors — designated B134, B135, B84, B136, and B137 — located under the steering column inside the instrument panel lower trim. The connector pinout and terminal assignments are therefore identical to those documented in the 2004 Impreza WRX factory service manual (Fuji Heavy Industries Pub. No. G1870GE3). The ECM draws a main 12 V supply with ignition on (B84-2), a permanent battery backup supply of 10–13 V (B84-10), and provides regulated 5 V sensor power (B84-3).

Connector D

PinnameSignal
D1Injector # 1Speed
D8Power GroundGround
D19O2 Sensor Signal (Front)Analog

Connector C

PinnameSignal
C4Injector # 4Speed
C5Injector # 3Speed
C6Injector # 2Speed
C8Power Ground (Injector)Ground
C9Tach SignalRPM
C18Power Ground (Coils)Ground

Connector E

PinnameSignal
E1Power GroundGround
E7Mass Air Flow Sensor GroundGround
E13Mass Air Flow SensorAnalog

Connector B

PinnameSignal
B7Throttle Position SensorAnalog
B8Manifold Atmospheric Pressure SensorAnalog
B17O2 Sensor Signal (Rear)Analog
B18Engine Coolant Temperature SensorAnalog
B19Sensor GroundGround
B27Intake Air Temperature SensorAnalog

Connector A

PinnameSignal
A1Vehicle Speed SensorSpeed

Notes

The ECM is located under the steering column inside the instrument panel lower trim panel. The turbo model (WRX/9-2X Aero) uses all five connectors (B134, B135, B84, B136, B137); non-turbo Impreza models use only B134, B135, and B136. Connector B84 is 31-pin, B134 is 28-pin, B135 is 22-pin, B136 is 17-pin, and B137 is 24-pin. The battery must be disconnected before ECM removal; fitting an ECM of the wrong specification will damage the fuel injection system.

Signals

  • Injector #1 — fuel injector drive output, connector D pin D1 (also B84-1 per OEM harness)
  • Power Ground — ECM power ground reference, connector D pin D8
  • O2 Sensor Signal (Front) — front air/fuel ratio (wideband) oxygen sensor signal input, connector D pin D19
  • Injector #4 — fuel injector #4 drive output, connector C pin C4
  • Injector #3 — fuel injector #3 drive output, connector C pin C5
  • Injector #2 — fuel injector #2 drive output, connector C pin C6
  • Power Ground (Injector) — injector circuit ground reference, connector C pin C8
  • Tach Signal — engine speed (tachometer) output signal, connector C pin C9
  • Power Ground (Coils) — ignition coil circuit ground reference, connector C pin C18
  • Power Ground — ECM power ground, connector E pin E1
  • Mass Air Flow Sensor Ground — MAF sensor shield/ground, connector E pin E7
  • Mass Air Flow Sensor — MAF sensor analogue signal input, connector E pin E13
  • Throttle Position Sensor — TPS analogue signal input, connector B pin B7
  • Manifold Atmospheric Pressure Sensor — manifold pressure sensor analogue signal input, connector B pin B8
  • O2 Sensor Signal (Rear) — rear (post-catalyst) oxygen sensor signal input, connector B pin B17
  • Engine Coolant Temperature Sensor — ECT sensor analogue signal input, connector B pin B18
  • Sensor Ground — 0 V reference for analogue sensors, connector B pin B19
  • Intake Air Temperature Sensor — IAT sensor analogue signal input, connector B pin B27
  • Vehicle Speed Sensor — vehicle speed pulse signal input, connector A pin A1

References

Category:Car Connectors