Dodge ZB 2005 Service Manual page 1200

P0172-1/1 FUEL SYSTEM RICH —
TEST
9 Note: For this test to be valid, the thermostat must be operating correctly.
Note: This test works best if performed on a cold engine (cold soak)
Ignition on, engine not running.
With the DRBIII , read the Engine Coolant Temperature Sensor value. If the engine
was allowed to sit overnight (cold soak), the temperature value should be a sensible
value that is somewhere close to the ambient temperature.
Note: If engine coolant temperature is above 82°C (180°F), allow the engine
to cool until 65°C (150°F) is reached.
Start the Engine.
During engine warm-up, monitor the Engine Coolant Temperature value. The temp
value change should be a smooth transition from start up to normal operating temp
82°C (180°F). The value should reach at least 82°C (180°F).
Did the Engine Coolant Temperature value increase smoothly and reach at least
82°C?
Yes → Go To 10
→ Replace the Engine Coolant Temperature Sensor.
No
10 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.
→ Refer to the INTERMITTENT CONDITION Symptom (Diagnos-
No
11 Disconnect the O2 Sensor harness connector.
Ignition on, engine not running.
With the DRBIII , monitor the O2 Sensor voltage.
Is the O2 Sensor voltage above 4.5 volts?
Yes → Replace the O2 Sensor.
→ Go To 12
No
12 Turn the ignition off.
Disconnect the PCM harness connectors.
Measure the resistance of the O2 Sensor Signal circuit from the PCM harness
connector to the O2 Sensor harness connector.
Is the resistance below 5.0 ohms?
Yes → Go To 13
→ Repair the open in the O2 Sensor Signal circuit.
No
Continued
ACTION
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
tic Procedure).
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
DRIVEABILITY - GAS
79
APPLICABILITY
All
All
All
All