P2172: The engine computer has seen a sudden jump in airflow that the throttle position can't account for, which usually means air is leaking in somewhere

Most likely causes

What to test first

Start at step 1. Each result tells you what it means and where to go next.

1. 1

   Step 1: Read all codes and check for bulletins covering your vehicle

   Low riskTool: OBD-II scan tool

   • IfA bulletin covers your vehicle

     It meansHave the dealer follow it before replacing parts.

     Go to step 2

   • IfP0107 or P0108 is also stored

     It meansCheck the MAP sensor circuit first.

     Points to: Faulty MAP sensor or its circuit

   • IfLean or fuel-trim codes too

     It meansLook for a vacuum leak.

     Go to step 2

2. 2

   Step 2: Inspect the intake boot, vacuum hoses and crankcase vent tubes, then smoke-test the intake

   Use cautionTool: Smoke machine

   Warning:Work on a cool engine and keep clear of the fan and belts if the engine is running.

   • IfCracked or disconnected vacuum hose or boot

     It meansRepair it.

     Points to: Vacuum leak: cracked hose, loose intake boot or leaking gasket

   • IfNo leak found

     It meansCheck the battery voltage and throttle.

     Go to step 3

3. 3

   Step 3: Check battery and charging voltage, then compare throttle position and MAP readings on the scan tool

   Best left to a shopTool: Multimeter, scan tool

   Warning:Keep clear of the fan and belts with the engine running, and don't short test leads across battery terminals.

   • IfVoltage low or unstable

     It meansRepair the charging or battery fault.

     Points to: Abnormal system voltage

   • IfMAP reading implausible

     It meansReplace or repair the MAP sensor circuit.

     Points to: Faulty MAP sensor or its circuit

Symptoms

• Check engine light
• Poor throttle response or hesitation
• Incorrect or rough idle
• Hard start or no start
• Stalling, loss of power or the transmission dropping into neutral Gets more serious: stop and have it checked.

Compare with: Check engine light with loss of power, Rough idle with the check engine light on

How to fix

1. 1

   Step 1: Ask a dealer to check your VIN for bulletins; Ram has published bulletins that list P2172.

2. 2

   Step 2: Check that the air intake duct between the filter box and the throttle body is attached and not cracked.

On your vehicle

Related codes

• P2173The engine computer has seen more airflow into the engine that the throttle position can't account for, which usually means air is leaking in somewhere

  Same system Supported by vehicle data

  Ram's bulletins describe P2172 and P2173 as the instantaneous and slow versions of the same airflow check.

• P219AThe engine computer has detected that the cylinders on bank 1 are running at noticeably different air-fuel ratios from each other

  Shares causes Supported by vehicle data

  Ram lists P219A with P2172/P2173 when the transmission drops to neutral.

• P0172Engine computer has reached its limit removing fuel on bank 1: the mixture is rich

  Shares causes Supported by vehicle data

  Ram lists rich fuel-trim codes P0172/P0175 alongside these airflow codes.

All Electronic throttle and accelerator pedal codes