Dodge Ram Truck 1500-2500-3500. Manual — part 974

P2097-DOWNSTREAM FUEL TRIM SYSTEM 1 RICH (CONTINUED)

2.

EXHAUST LEAK

Turn the ignition off.

WARNING: To avoid personal injury from the exhaust system being hot, allow the exhaust to cool down to
a safe temperature before performing a physical inspection. Failure to follow these instructions can result in
personal injury or death.
Visually and Physically inspect the exhaust system for holes, cracks and blockage in the exhaust system.

Is the exhaust system is good condition?

Yes

>> Go To 3

No

>> Repair or Replace as necessary.

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

3.

ENGINE MECHANICAL

Check for any of the following conditions/mechanical problems

AIR INDUCTION SYSTEM - must be free from leaks.

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

>> Go To 4

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ENGINE - ELECTRICAL DIAGNOSTICS - 3.7L/4.7L/5.7L

DR/DH

P2097-DOWNSTREAM FUEL TRIM SYSTEM 1 RICH (CONTINUED)

4.

O2 SENSOR

Ignition on, engine not running.

Disconnect the 1/2 O2 Sensor harness connector.

With the scan tool, monitor the 1/2 O2 Sensor voltage.

The O2 Sensor voltage should read 5.0 volts on the scan tool with the
connector disconnected.

Using a jumper wire, jump the (K141) O2 Sensor 1/2 Signal circuit to
the (K904) O2 Return Downstream circuit in the O2 Sensor harness
connector.

NOTE: The voltage should drop from 5.0 volts to 2.5 volts with
the jumper wire in place.

Did the O2 Sensor volts change from 5.0 volts to 2.5 volts?

Yes

>> Replace the O2 Sensor.

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

No

>> Go To 5

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - 3.7L/4.7L/5.7L

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P2097-DOWNSTREAM FUEL TRIM SYSTEM 1 RICH (CONTINUED)

5.

(K141) O2 SENSOR 1/2 SIGNAL CIRCUIT

Remove the jump wire.

Ignition on, engine not running.

With the scan tool, monitor the 1/2 O2 Sensor voltage.

Is the voltage above 4.8 volts?

Yes

>> Go To 6

No

>> Check the (K141) O2 Sensor 1/2 Signal circuit for an open

or short to voltage. Inspect the O2 Sensor connector and
the PCM harness connector. If OK, 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 - 3.7L/4.7L/5.7L

DR/DH

P2097-DOWNSTREAM FUEL TRIM SYSTEM 1 RICH (CONTINUED)

6.

(K299) O2 SENSOR 1/2 HEATER CONTROL CIRCUIT OPEN

Turn the ignition off.

Disconnect the C3 PCM harness connector.

Measure the resistance of the (K299) O2 Sensor 1/2 Heater Control
circuit from the O2 Sensor harness connector to the appropriate ter-
minal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes

>> Go To 7

No

>> Repair the open in the (K299) O2 Sensor 1/2 Heater Con-

trol circuit.

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

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - 3.7L/4.7L/5.7L

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