P2173
P2173 - High Airflow-Vacuum Leak Detected, Slow Accumulation
For wiring diagrams, refer to.
• When Monitored: Ignition on and engine running with no MAP sensor DTCs.
• Set Condition: A large vacuum leak has been detected or the signal voltage for both TP sensors is stuck at 2.5 Volts and calculated MAP is less than the Gas Flow Adaptation value. One trip fault; the DTC will set within 5 seconds. ETC light will flash.
• Always perform the pre-diagnostic troubleshooting procedure before proceeding. Refer to => Non-DTC Based Diagnostics. Pre-Diagnostic Troubleshooting Procedure
Test Step 1 - Active DTC
• Diagnose and repair any ETC, MAP Sensor, VSS, or 5 Volt supply circuit DTCs before continuing.
• Start the engine and allow it to reach normal operating temperature.
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
• Using the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
• Go to Test Step 2 => [ Test
Step 2 - Vacuum Leak ]
No
• The DTC is not active at this time. Refer to the checking for an intermittent DTC diagnostic procedure. Refer => Non-DTC Based Diagnostics.
Test Step 2 - Vacuum Leak
• This DTC is enabled on engines equipped with a plastic intake manifold to limit engine operation if a large vacuum leak should occur.
• A large vacuum leak is the most probable cause of this DTC.
• Inspect the intake manifold, power brake booster, and PCV system for any vacuum leaks.
• Inspect the MAP sensor and throttle body for proper installation.
• Inspect the engine for any mechanical conditions that can cause improper engine vacuum.
Were any problems found?
Yes
• Repair as necessary.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Go to Test Step 3 => [ Test
Step 3 - MAP Sensor Operation ]
Test Step 3 - MAP Sensor Operation
• Start the engine.
• With a scan tool, monitor the MAP sensor voltage.
• Snap the throttle.
Does the MAP Sensor voltage vary from less than 2.0 volts at idle to more than 3.5 volts at wide open throttle?
Yes
• Go to Test Step 5 => [ Test
Step 5 - PCM ]
No
• Go to Test Step 4 => [ Test
Step 4 - MAP Sensor ]
Test Step 4 - MAP Sensor
• Turn the ignition OFF.
• Disconnect the MAP sensor harness connector.
• Disconnect the PCM harness connector.
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the MAP sensor and the powertrain control module.
• Look for any chafed, pierced, pinched, or partially broken wires.
• Look for broken, bent, pushed out or corroded terminals.
• Check each of the MAP sensor circuits for high resistance or a shorted condition.
Were any problems found?
Yes
• Repair as necessary.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Replace the MAP sensor.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 5 - PCM
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the MAP sensor and the PCM and between the throttle body and the PCM.
• Look for any chafed, pierced, pinched, or partially broken wires.
• Look for broken, bent, pushed out or corroded terminals.
• Refer to any technical service bulletins that may apply.
Were any problems found?
Yes
• Repair as necessary.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics . PCM Verification Test
No
• Replace and program the PCM.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test