Dodge Ram Truck 1500-2500-3500. Manual — part 1182

P0172-FUEL SYSTEM 1/1 RICH (CONTINUED)

10.

ENGINE MECHANICAL PROBLEM

Check for any of the following conditions/mechanical problems.

AIR INDUCTION SYSTEM - must be free from restrictions.

ENGINE VACUUM - must be at least 13 inches in neutral

ENGINE VALVE TIMING - must be within specifications

ENGINE COMPRESSION - must be within specifications

ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks.

ENGINE PCV SYSTEM - must flow freely

TORQUE CONVERTER STALL SPEED - must be within specifications

POWER BRAKE BOOSTER - no internal vacuum leaks

FUEL - must be free of contamination

FUEL INJECTOR - plugged or restricted injector; control wire not connected to correct injector

Are there any engine mechanical problems?

Yes

>> Repair as necessary.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

11.

O2 SENSOR

Disconnect the sensor harness connector of the O2 Sensor(s) that had a voltage value greater than 4.5 volts in the
previous step.

Ignition on, engine not running.

With the scan tool, monitor the O2 Sensor voltage reading(s).

Is the O2 Sensor voltage above 4.5 volts?

Yes

>> Replace the O2 Sensor.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Go To 12

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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P0172-FUEL SYSTEM 1/1 RICH (CONTINUED)

12.

(K41) O2 SENSOR 1/1 SIGNAL CIRCUIT OPEN

Turn the ignition off.

Disconnect the PCM harness connectors.

Measure the resistance of the (K41) O2 Sensor 1/1 Signal circuit from
the PCM harness connector to the O2 Sensor harness connector.

Is the resistance below 5.0 ohms?

Yes

>> Go To 13

No

>> Repair the open in the (K41) O2 Sensor 1/1 Signal circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

13.

(K41) O2 SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO VOLTAGE

Ignition on, engine not running.

Leave the O2 Sensor and PCM harness connectors disconnected.

Measure the voltage on the (K41) O2 Sensor 1/1 Signal circuit at the
1/1 O2 Sensor harness connector.

Is the voltage above 5.2 volts?

Yes

>> Repair the short to voltage in the O2 Sensor Signal circuit.

Perform the POWERTRAIN VERIFICATION TEST. (Refer
to 9 - ENGINE - STANDARD PROCEDURE)

No

>> Go To 14

NOTE: Turn the ignition off before continuing.

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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P0172-FUEL SYSTEM 1/1 RICH (CONTINUED)

14.

PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.

If there are no possible causes remaining, view repair.

Repair

Replace and program the Powertrain Control Module per Service Information.

Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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P0174-FUEL SYSTEM 2/1 LEAN

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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