P2173

DTC P2173: Abnormal Intake Air Amount

TECHNICAL DESCRIPTION
- ECM or PCM decides the allowable intake air amount in accordance with the engine speed and the target opening angle of throttle valve.
- ECM or PCM checks whether the actual intake air amount is more than the allowable intake air amount.

DESCRIPTIONS OF MONITOR METHODS
The actual intake air amount is more than the allowable intake air amount.

MONITOR EXECUTION
Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
- Not applicable

Sensor (The sensor below is determined to be normal)
- Not applicable

DTC SET CONDITIONS

Check Condition
- 3 seconds or more have passed since the engine starting sequence was completed.

Judgement Criterion
- The actual intake air amount is more than the allowable intake air amount for 1.5 seconds.

OBD-II DRIVE CYCLE PATTERN
None.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Mass airflow sensor failed.
- Throttle valve faulty operation.
- Throttle position sensor failed.
- ECM failed.
- PCM failed.

DIAGNOSIS

Required Special Tools
- MB991958: Scan tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B

STEP 1. Using scan tool MB991958, read the diagnostic trouble code (DTC).

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991958, read the DTC.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the diagnostic trouble code other than P2173 output?

YES: Refer to, Diagnostic Trouble Code Chart Diagnostic Trouble Code Descriptions.

NO: Go to Step 2.

STEP 2. Replace the mass airflow sensor.

1. Replace the mass airflow sensor.
2. Turn the ignition switch to the "ON" position.
3. Erase the DTC.
4. Start the engine and run at idle for a few seconds.
5. Read the DTC.
6. Turn the ignition switch to the "OFF" position.

Q: Is DTC P2173 set?

YES: Go to Step 3.

NO: The inspection is complete.

STEP 3. Replace the throttle body assembly.

1. Replace the throttle body assembly.
2. Turn the ignition switch to the "ON" position.
3. Erase the DTC.
4. Start the engine and run at idle for a few seconds.
5. Read the DTC.
6. Turn the ignition switch to the "OFF" position.

Q: Is DTC P2173 set?

YES: Replace the ECM or the PCM, then Go to Step 4.

NO: The inspection is complete.

STEP 4. Using scan tool MB991958, read the DTC.

1. Turn the ignition switch to the "ON" position.
2. Erase the DTC.
3. Start the engine and run at idle for a few seconds.
4. Read the DTC.
5. Turn the ignition switch to the "OFF" position.

Q: Is DTC P2173 set?

YES: Retry the troubleshooting.

NO: The inspection is complete.