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Home >> Suzuki >> 2005 >> Aerio S, Standard >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine General Information And Diagnosis >> DTC P0451: Evaporative Emission Control System Pressure Sensor Range/Performance >> Diagnostic Trouble Codes Troubleshooting
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Diagnostic Trouble Codes Troubleshooting

WARNING: In order to reduce risk of fire and personal injury, this work must be performed in a well ventilated area and away from any open flames such as gas hot water.
DTC TROUBLESHOOTING

Step Action Yes No
1 Was "Engine and Emission Control System Check" performed?  Go To Step 2. Go to "ENGINE AND EMISSION CONTROL SYSTEM CHECK :".
2 Do you have SUZUKI scan tool?  Go To Step 3. Go To Step 4.
3 Check fuel tank pressure and temp, sensor and its circuit 
  1. Connect SUZUKI scan tool to DLC with ignition switch turned OFF.
  2. Open fuel filler cap and turn ON ignition switch.

Is tank pressure displayed about 0 kPa (0 mmHg)? 		 Go To Step 16. Go To Step 4.
4 Check fuel tank pressure and temp, sensor circuit 
  1. Open fuel filler cap and turn ON ignition switch.
  2. Remove ECM from vehicle body referring to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION and connect connectors to ECM.
  3. Measure voltage at "G04-19" terminal of ECM connector.

Is it about 2.0 - 3.0 V? 		 Check poor connection at "G04-19" terminal of ECM connector. If OK, Go To Step 16. Go To Step 5.
5 Check fuel tank pressure and temp, sensor power supply voltage 
  1. Remove fuel tank referring to FUEL TANK REMOVAL AND INSTALLATION .
  2. Disconnect connector from fuel tank pressure and temp, sensor with ignition switch turned OFF.
  3. Check for proper connection to fuel tank pressure and temp, sensor at "GRY/RED" and "ORN" wire terminals.
  4. If OK, then turn ON ignition switch, measure voltage between "GRY/RED" wire terminal of fuel tank pressure and temp, sensor connector and vehicle body ground.

Is voltage about 4 - 6 V? 		 Go To Step 8. Go To Step 6.
6 Check ECM voltage 
  1. Disconnect connectors from ECM with ignition switch turned OFF.
  2. Remove ECM from vehicle body referring to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION and connect connectors to ECM.
  3. Check for proper connection of ECM connector at "C46-23" terminal.
  4. If OK, then turn ON ignition switch, measure voltage between "C46-23" terminal of ECM connector and vehicle body ground.

Is voltage about 4 - 6 V? 		 Open wire in "GRY/ RED" circuit. If wire and connection are OK, Go To Step 7. Go To Step 7.
7 Check ECM voltage 
  1. Disconnect connectors from TP sensor and MAP sensor with ignition switch turned OFF.
  2. Turn ON ignition switch, check voltage between "C46-23" terminal of ECM connector and vehicle body ground.

Is voltage about 4 - 6 V? 		 Faulty MAP sensor and/ or TP sensor.
Check MAP sensor and/ or TP sensor.		 Go To Step 8.
8 Check wire circuit 
  1. Disconnect connectors from ECM with ignition switch turned OFF.
  2. Turn ON ignition switch.
  3. Measure voltage between "GRY/RED" wire terminal of fuel tank pressure and temp, sensor connector and vehicle body ground.

Is voltage about 0 V? 		 Go To Step 9. "GRY/RED" wire shorted to other circuits.
If wire are OK, substitute a known-good ECM and recheck.
9 Check wire circuit 
  1. Measure resistance between "GRY/RED" wire terminal of fuel tank pressure and temp, sensor connector and vehicle body ground with ignition switch turned OFF.

Is resistance infinity? 		 Go To Step 10. "GRY/RED" wire shorted to ground circuit.
10 Check wire circuit 
  1. Measure resistance between "C46-23" terminal of ECM connector and "GRY/RED" wire terminal of fuel tank pressure and temp, sensor connector with ignition switch turned OFF.

Is resistance below 5 Ω? 		 Go To Step 11. High resistance wire in "GRY/RED" circuit.
11 Check ground circuit 
  1. Connect connectors to ECM.
  2. Check for proper connection of fuel tank pressure and temp, sensor at "ORN" wire terminal.
  3. Measure resistance between "ORN" wire terminal of fuel tank pressure and temp, sensor connector and body ground.

Is resistance below 10 Ω? 		 Go To Step 13. Go To Step 12.
12 Check ground circuit 
  1. Measure resistance between "G04-15" terminal of ECM connector and body ground.

Is resistance below 5 Ω? 		 Open or high resistance wire in "ORN" circuit.
Poor "G04-15" terminal of ECM connector connection.		 Faulty ECM ground circuit.
If circuit are OK, substitute a known-good ECM and recheck.
13 Check wire circuit 
  1. Disconnect connectors from ECM with ignition switch turned OFF.
  2. Turn ON ignition switch.
  3. Measure voltage between "RED/YEL" wire terminal of fuel tank pressure and temp, sensor connector and vehicle body ground.

Is voltage about 0 V? 		 Go To Step 14. "RED/YEL" wire shorted to other circuits.
If wire are OK, substitute a known-good ECM and recheck.
14 Check wire circuit 
  1. Measure resistance between "RED/YEL" wire terminal of fuel tank pressure and temp, sensor connector and vehicle body ground with ignition switch turned OFF.

Is resistance infinity? 		 Go To Step 15. "RED/YEL" wire shorted to ground circuit.
15 Check wire circuit 
  1. Measure resistance between "G04-19" terminal of ECM connector and "RED/YEL" wire terminal of fuel tank pressure and temp, sensor connector with ignition switch turned OFF.

Is resistance below 5 Ω? 		 Go To Step 16. High resistance wire in "RED/YEL" circuit.
16
  1. Check fuel tank pressure and temp, sensor according to "FUEL TANK PRESSURE AND TEMP. SENSOR INSPECTION .
Is it in good condition? 		 Go To Step 17. Replace fuel tank pressure and temp, sensor.
17
  1. Check the following parts for clog.
    • Check the EVAP canister.
    • Check the EVAP canister air suction filter.
    • Check the EVAP canister air suction passage.
    • Check the Fuel vapor passage between tank and canister.
Is check result satisfactory? 		 Faulty ECM.
Substitute a known-good ECM and recheck.		 Clean, repair or replace.
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