Page 916 of 5267

INTERMITTENT CONDITION
For a complete wiring diagramRefer 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 notwear 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 scantool parameters relatedtotheDTCwhile
wiggling the wire harness. Look for parameter values to change and/or a DTCto 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, orcorroded 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 andphysical 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 diagnoseintermittent conditions.
Were any problems found during the above inspections?
Ye s>>
Perform the necessary repairs.
Perform POWERTRAIN VERIFICATION TEST VER - 1.
No>>
Te s t C o m p l e t e .
Page 920 of 5267
5.(K99) HEATER CONTROL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K99) O2 Heater Con-
trol (PWM) circuit.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the Heater Control (PWM) cir-
cuit or the Heater Relay Control circuit depending on the O2
Sensor being tested.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 6
6.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.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 924 of 5267
5.HEATER CONTROL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the O2 Heater Control
(PWM) circuit.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the Heater Control (PWM) cir-
cuit or the Heater Relay Control circuit depending on the O2
Sensor being tested.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 6
6.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.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 928 of 5267
5.(K199) HEATER CONTROL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K199) O2 Heater
Control (PWM) circuit.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (K199) Heater Control
(PWM) circuit or the Heater Relay Control circuit depending
on the O2 Sensor being tested.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 6
6.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.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 932 of 5267
5.(K199) HEATER CONTROL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K199) O2 Heater
Control (PWM) circuit.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (K199) Heater Control
(PWM) circuit or the Heater Relay Control circuit depending
on the O2 Sensor being tested.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 6
6.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.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 937 of 5267
8.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.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 942 of 5267
8.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?
Ye s>>
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)
Page 947 of 5267
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?
Ye s>>
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)