Dodge Ram Truck 1500-2500-3500. Manual — part 1142

INTERMITTENT CONDITION

For the Engine circuit diagrams (Refer to 9 - ENGINE - SCHEMATICS AND DIAGRAMS).

For a complete wiring diagram Refer to Section 8W.

POSSIBLE CAUSES

INTERMITTENT CONDITION

Diagnostic Test

1.

INTERMITTENT CONDITION

NOTE: The conditions that set the DTC are not present at this time. The following list may help in identi-
fying the intermittent condition.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands
near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in
personal injury or death.
Refer to any Technical Service Bulletins (TSBs) that may apply.

Review the scan tool Freeze Frame information. If possible, try to duplicate the conditions under which the DTC set.

With the engine running at normal operating temperature, monitor the scan tool parameters related to the DTC while
wiggling the wire harness. Look for parameter values to change and/or a DTC to set.

Turn the ignition off.

Visually inspect the related wire harness. Disconnect all the related harness connectors. Look for any chafed,
pierced, pinched, partially broken wires and broken, bent, pushed out, or corroded terminals.

Perform a voltage drop test on the related circuits between the suspected faulty component and the PCM.

Inspect and clean all PCM, engine, and chassis grounds that are related to the most current DTC.

If numerous trouble codes were set, use a wire schematic and look for any common ground or supply circuits.

For any Relay DTCs, actuate the Relay with the scan tool and wiggle the related wire harness to try to interrupt the
actuation.

For intermittent Evaporative Emission trouble codes perform a visual and physical inspection of the related parts
including hoses and the Fuel Filler cap.

For intermittent Misfire DTC’s check for restrictions in the Intake and Exhaust system, proper installation of Sensors,
vacuum leaks, and binding components that are run by the accessory drive belt.

Use the scan tool to perform a System Test if one applies to failing component.

A co-pilot, data recorder, and/or lab scope should be used to help diagnose intermittent conditions.

Were any problems found during the above inspections?

Yes

>> Perform the necessary repairs.

Perform POWERTRAIN VERIFICATION TEST VER - 1.

No

>> Test Complete.

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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P0031-O2 SENSOR 1/1 HEATER CIRCUIT LOW

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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P0031-O2 SENSOR 1/1 HEATER CIRCUIT LOW (CONTINUED)

For the Engine circuit diagram (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/ENGINE CON-
TROL MODULE - SCHEMATIC - ELECTRICAL)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
Battery voltage above 10.6 volts, ASD is powered up, and O2 heater is on.

•

Set Condition:
Desired state does not match Actual state.

Possible Causes

O2 HEATER TEST

O2 SENSOR HEATER ELEMENT

(K343) FUSED ASD RELAY OUTPUT CIRCUIT

(K99) HEATER CONTROL CIRCUIT OPEN

(K99) HEATER CONTROL CIRCUIT SHORTED TO GROUND

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)

1.

O2 HEATER TEST

Ignition on, engine not running.

With the scan tool, read DTCs and record the related Freeze Frame data.

With the scan tool, actuate the O2 Heater test.

Monitor the O2 Heater Voltage for 5 minutes.

Did the voltage drop down close to zero during the Heater test?

Yes

>> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.

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

No

>> Go To 2

NOTE: Stop the actuation before continuing.

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ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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P0031-O2 SENSOR 1/1 HEATER CIRCUIT LOW (CONTINUED)

2.

O2 HEATER ELEMENT

Turn the ignition off.

Disconnect the O2 Sensor harness connector.

Measure the resistance of the O2 Heater element at the O2 Sensor
connector (component side).

On a four O2 Sensor system the resistance value for 1/1 and 2/1 O2
Heater elements is between 3.3 and 4.1 ohms and the 1/2 and 2/2 O2
Heater elements is between 4.0 and 5.0 ohms at 70° F(21.1°C).

NOTE: The resistance value will increase with warmer tempera-
tures.

Is the resistance within the listed specifications?

Yes

>> Go To 3

No

>> Replace the O2 Sensor.

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

3.

(K343) FUSED ASD RELAY OUTPUT CIRCUIT OPEN

Ignition on, engine not running.

With the scan tool, actuate the O2 Heater Test.

Using a 12-volt test light connected to ground, probe the (K343) Fused
ASD Relay Output circuit at the O2 Sensor harness connector.

Did the test light illuminate brightly?

Yes

>> Go To 4

No

>> Repair the open or short to ground in the (K343) Fused

ASD Relay Output circuit. Inspect the related fuse and
repair as necessary.

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

NOTE: Stop the actuation before continuing.

DR/DH

ENGINE - ELECTRICAL DIAGNOSTICS - SRT-10

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