Chrysler PT Cruiser 2001 Service Manual Supplement page 2548

DRIVEABILITY - GAS
P0171-1/1 FUEL SYSTEM LEAN —
TEST
6 Start the engine.
Allow the engine to reach normal operating temperature.
With the DRBIII , read O2 Sensor voltage.
Raise and lower the RPM.
Allow the vehicle to idle.
Does the O2 Sensor voltage vary from below .35 volts to above .53 volts.
Yes → Go To 7
→ Go To 13
No
7 Turn the ignition on.
With the DRBIII , read TPS VOLTS.
While monitoring the DRBIII , slowly open and close the Throttle.
Is the voltage change smooth?
Yes → Go To 8
→ Replace the Throttle Position Sensor.
No
8 Turn the ignition on.
With the DRB, read TPS VOLTS. Throttle must be against stop.
Is the voltage 0.92 or less with the Throttle closed?
Yes → Go To 9
→ Check for a binding throttle condition. If OK, replace the Throttle
No
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 soaked).
Turn the ignition on.
With the DRB, read the ENG COOLANT TMP DEG value. If the engine was allowed
to sit overnight (cold soak), the engine temperature value should be a sensible value
that is close to the surrounding temperature (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 ENG COOLANT TMP DEG value. The temp
deg 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 ENG COOLANT TMP DEG value increase smoothly and did it reach at least
82° C (180° F)?
Yes → Go To 10
→ Replace the Engine Coolant Temperature Sensor.
No
Continued
ACTION
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Position Sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
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APPLICABILITY
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