Jeep Wrangler TJ. Manual - part 136

TEST

ACTION

APPLICABILITY

Turn the ignition off.
Disconnect the PCM harness connectors.
Disconnect the SKIM harness connector.
CAUTION: DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING
THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMI-
NALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL
MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS.
Measure the resistance of the PCI Bus circuit from the SKIM harness connector to
the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

All

Yes

→ Go To 4

→ Repair the open in the PCI Bus circuit between the PCM and the

SKIM.
Perform SKIS VERIFICATION.

Connect the PCM harness connectors.
Replace the Sentry Key Immobilizer Module in accordance with the Service Infor-
mation.
Ignition on, engine not running.
Display and erase all PCM and SKIM DTCs.
Perform 5 ignition key cycles leaving the ignition key on for 90 seconds per cycle.
With the DRB, display PCM DTCs.
Does the DRB display the same DTC?

All

Yes

→ Replace and program the Powertrain Control Moldule per service

Information.
Perform SKIS VERIFICATION.

→ Test Complete.

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DRIVEABILITY - NGC

U0168-NO SKIM BUS MESSAGE —

Continued

Symptom:

*CHECKING A/C SYSTEM OPERATION WITH NO DTCS

POSSIBLE CAUSES

CHECK FOR PCM DTCS

REFRIGERATION SYSTEM NOT PROPERLY CHARGED

HIGH PRESS CUT-OFF SWITCH

LOW PRESSURE SWITCH

POWERTRAIN CONTROL MODULE

A/C CLUTCH COIL

A/C COMPRESSOR CLUTCH GROUND CIRCUIT OPEN

(C3) A/C CLUTCH RELAY OUTPUT CIRCUIT OPEN

A/C REQUEST CIRCUIT OPEN

(A17) FUSED B+ CIRCUIT OPEN

A/C CLUTCH RELAY

A/C - HEATER CONTROL MODULE

BODY CONTROL MODULE

A/C ON/OFF CONTROL CIRCUIT OPEN

TEST

ACTION

APPLICABILITY

With the DRBIII

t, check for PCM DTCs.

Are any DTCs present?

All

Yes

→ Return to the symptom list and choose the symptom(s).

Perform POWERTRAIN VERIFICATION TEST VER - 2.

→ Go To 2

Turn the ignition off.
Verify that the Refrigerant System is properly charged per Service Procedure.
Is the Refrigerant System properly charged?

All

Yes

→ Go To 3

→ Properly charge the Refrigerant System per Service Information.

Perform POWERTRAIN VERIFICATION TEST VER - 2.

Verify the High Pressure Cut-Off Switch operation per Service Information.
Is the High Pressure Cut-Off Switch OK?

All

Yes

→ Go To 4

→ Replace the High Pressure Cut-Off Switch.

Perform POWERTRAIN VERIFICATION TEST VER - 2.

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DRIVEABILITY - NGC

TEST

ACTION

APPLICABILITY

Verify the Low Pressure Switch operation per Service Information.
Is the Low Pressure Switch OK?

All

Yes

→ Go To 5

→ Replace the Low Pressure Switch.

Perform POWERTRAIN VERIFICATION TEST VER - 2.

Ignition on, engine not running.
Position the Mode switch on the A/C - Heater Control Module to the Panel position.
With the DRBIII

t in BCM, select Inputs/Outputs.

Monitor the A/C Select Switch state while pressing the A/C mode switch on and off.
Does the A/C Select Switch state change accordingly.

All

Yes

→ Go To 6

→ Go To 13

Position the Mode switch on the A/C - Heater Control Module to the Panel position.
With the DRBIII

t in Powertrain, select Engine and select Inputs/Outputs.

Monitor the A/C Select Switch state while pressing the A/C mode switch on and off.
Does the A/C Select Switch state change accordingly.

All

Yes

→ Go To 7

→ Replace and program the Powertrain Control Module per Service

Information.
Perform POWERTRAIN VERIFICATION TEST VER - 2.

Connect a test light between the ground circuit and the A/C Clutch Relay Output
circuit.
With the DRBIII

t, actuate the A/C Clutch Relay.

Does the test light illuminate brightly on and off with the relay actuation?

All

Yes

→ Replace the A/C Clutch Coil.

Perform POWERTRAIN VERIFICATION TEST VER - 2.

→ Go To 8

Turn the ignition off.
Disconnect the A/C Clutch harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between ground and the A/C Compressor Clutch ground
circuit in the A/C Clutch harness connector.
Is the resistance below 5.0 ohms?

All

Yes

→ Go To 9

→ Repair the open in the A/C Compressor Clutch ground circuit.

Perform POWERTRAIN VERIFICATION TEST VER - 2.

Turn the ignition off.
Remove the A/C Clutch Relay.
Note: Check connectors - Clean/repair as necessary.
Measure the resistance of the (C3) A/C Clutch Relay Output circuit between the
Relay and the A/C Clutch Coil.
Is the resistance below 5.0 ohms?

All

Yes

→ Go To 10

→ Repair the open in the (C3) A/C Clutch Relay Output circuit.

Perform POWERTRAIN VERIFICATION TEST VER - 2.

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DRIVEABILITY - NGC

*CHECKING A/C SYSTEM OPERATION WITH NO DTCS —

Continued

TEST

ACTION

APPLICABILITY

Engine Running.
Turn the A/C system on and the fan on high.
With the DRBIII

t in Inputs/Outputs, read the A/C request state.

Does the A/C request state change?

All

Yes

→ Go To 11

→ Repair the open in the A/C Request circuit.

Perform POWERTRAIN VERIFICATION TEST VER - 2.

Turn the ignition off.
Remove the A/C Clutch Relay.
Note: Check connectors - Clean/repair as necessary.
Measure the voltage of the (A17) Fused B+ circuit at the A/C Clutch Relay connector.
Is the voltage above 11.0 volts?

All

Yes

→ Go To 12

→ Repair the open in the (A17) Fused B+ circuit.

Perform POWERTRAIN VERIFICATION TEST VER - 2.

If there are no possible causes remaining, view repair.

All

Repair

Replace the A/C Clutch Relay.
Perform POWERTRAIN VERIFICATION TEST VER - 2.

Turn the ignition off.
Disconnect the A/C - Heater Control C1 harness connector.
Ignition on, engine not running.
Measure the voltage between the A/C On/Off Control circuit and ground.
Is the voltage greater than 11.0 volts?

All

Yes

→ Go To 14

→ Go To 15

Turn the ignition off.
Disconnect the A/C - Heater Control C1 harness connector.
Ignition on, engine not running.
With the DRBIII

t in BCM, select Inputs/Outputs.

Monitor the A/C Select Switch state while connecting a jumper wire between ground
and the A/C On/Off Control circuit in the A/C - Heater Control C1 harness connector.
Does the A/C Select Switch state change from

9Off9 to 9On9 when the jumper wire is

connected.

All

Yes

→ Replace the A/C - Heater Control Module in accordance with the

Service Information.
Perform BODY VERIFICATION TEST - VER 1.

→ Replace and program the Body Control Module per Service

Information.
Perform BODY VERIFICATION TEST - VER 1.

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DRIVEABILITY - NGC

*CHECKING A/C SYSTEM OPERATION WITH NO DTCS —

Continued

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