Jeep Grand Cherokee WK. Manual — part 863

P0058-O2 SENSOR 2/2 HEATER CIRCUIT HIGH (CONTINUED)

3.

(K399) O2 2/2 HEATER CONTROL CIRCUIT

Ignition on, engine not running.

With a scan tool, actuate the O2 2/2 Heater Test with the Sensor har-
ness connector still disconnected.

Using a 12-volt test light connected to ground, probe the (K399) O2
2/2 Heater Control circuit in the O2 Sensor harness connector.

Does the test light illuminate brightly and flash on and off dur-
ing the actuation?

Yes

>> Go To 4

No

>> Go To 5

4.

(Z42) O2 HEATER GROUND CIRCUIT OPEN

Turn the ignition off.

Measure the resistance between an engine ground and the (Z42) O2
2/2 Heater ground circuit in the O2 Sensor harness connector.

Is the resistance below 5.0 ohms?

Yes

>> Replace the O2 Sensor.

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

No

>> Repair the open in the (Z42) O2 2/2 Heater ground circuit.

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

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ENGINE ELECTRICAL DIAGNOSTICS

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P0058-O2 SENSOR 2/2 HEATER CIRCUIT HIGH (CONTINUED)

5.

(K399) O2 2/2 HEATER CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE

Turn the ignition off.

Disconnect the C3 PCM harness connector.

Ignition on, engine not running.

Using a 12-volt test light connected to ground, probe the (K399) O2
Heater 2/2 Control circuit in the O2 Sensor harness connector.

Does the test light illuminate?

Yes

>> Repair the short to battery voltage in the (K399) O2 2/2

Heater Control circuit.

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

No

>> Go To 6

6.

(K399) O2 2/2 HEATER CONTROL CIRCUIT OPEN

Turn the ignition off.

CAUTION: Do not probe the PCM harness connectors. Probing
the PCM hanrness connectors will damage the PCM terminals
resulting in poor terminal to pin connection. Install Miller Special
Tool #8815 to perform diagnosis.
Measure the resistance of the (K399) O2 2/2 Heater Control circuit
from the O2 Sensor harness connector to the appropriate terminal of
special tool #8815.

Is the resistance below 5.0 ohms?

Yes

>> Go To 7

No

>> Repair the open in the (K399) O2 2/2 Heater Control cir-

cuit.

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

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ENGINE ELECTRICAL DIAGNOSTICS

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P0058-O2 SENSOR 2/2 HEATER CIRCUIT HIGH (CONTINUED)

7.

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.

Were there any problems found?

Yes

>> Repair as necessary.

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

No

>> 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

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P0068-MANIFOLD PRESSURE/THROTTLE POSITION CORRELATION

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ENGINE ELECTRICAL DIAGNOSTICS

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