Jeep Wrangler TJ. Manual - part 107

TEST

ACTION

APPLICABILITY

Turn the ignition off.
Connect the Evap Purge Solenoid harness connector.
Disconnect the vacuum hoses at the Evap Purge Solenoid.
NOTE: After disconnecting the Evap Purge Solenoid vacuum connections,
inspect the lines and solenoid for any signs of contamination from the EVAP
Canister. This may indicate a faulty rollover valve. Replace/repair as
necessary.
Using a hand vacuum pump, apply 10 in Hg to the

9CAN9 of the EVAP Purge

Solenoid.
NOTE: Monitor the vacuum gauge for at least 15 seconds.
Does the EVAP Purge Solenoid hold vacuum?

All

Yes

→ Go To 4

→ Replace the Evap Purge Solenoid.

Perform POWERTRAIN VERIFICATION TEST VER - 5.

Ignition on, engine not running.
Using the DRBIII

t, monitor the NVLD Switch State with the vacuum pump still

installed and holding vacuum.
Does the DRBIII

t display the NVLD state OPEN?

All

Yes

→ Refer to the INTERMITTENT CONDITION Symptom (Diagnos-

tic Procedure).
Perform POWERTRAIN VERIFICATION TEST VER - 5.

→ Go To 5

NOTE: Remove the vacuum pump and connect the vacuum hose before
continuing.

Disconnect the NVLD electrical connector.
Does the Switch change from CLOSED to OPEN?

All

Yes

→ Replace the NVLD Assembly.

Perform POWERTRAIN VERIFICATION TEST VER - 5.

→ Go To 6

Turn the ignition off.
Disconnect the C3 PCM harness connector.
Measure the resistance between ground and the (K107) NVLD Switch Signal circuit
in the NVLD Assembly harness connector.
Is the resistance below 5.0 ohms?

All

Yes

→ Repair the short to ground in the (K107) NVLD Switch Signal

circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.

→ Go To 8

Turn the ignition off.
Disconnect the C3 PCM harness connector.
Measure the resistance between ground and the (K52) Evap Purge Sol Control circuit
at the EVAP Purge Solenoid harness connector.
Is the resistance below 5.0 ohms?

All

Yes

→ Repair the short to ground in the (K52) Evap Purge Sol Control

circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.

→ Go To 8

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P0452-NVLD PRESSURE SWITCH STUCK CLOSED —

Continued

TEST

ACTION

APPLICABILITY

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.

All

Repair

Replace and program the Powertrain Control Module per Service
Information.
Perform POWERTRAIN VERIFICATION TEST VER - 5.

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P0452-NVLD PRESSURE SWITCH STUCK CLOSED —

Continued

Symptom:

P0453-NVLD PRESSURE SWITCH STUCK OPEN

When Monitored and Set Condition:

P0453-NVLD PRESSURE SWITCH STUCK OPEN

When Monitored:

Engine running.

Set Condition:

If the PCM does not see the NVLD switch close during test an error is

detected. One Trip Fault.

POSSIBLE CAUSES

NVLD SWITCH OPERATION

NVLD ASSEMBLY

(K107) NVLD SWITCH SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

(K107) NVLD SWITCH SIGNAL CIRCUIT OPEN

(K107) NVLD SWITCH SIGNAL CIRCUIT SHORTED TO THE (K106) SOLENOID CONTROL CIR-
CUIT

(Z913) GROUND CIRCUIT OPEN

PCM

TEST

ACTION

APPLICABILITY

Check for any related TSBs before continuing.
Start the engine.
Allow the engine to idle.
Using the DRBIII

t, perform the NVLD FORCED MONITOR TEST.

Monitor the NVLD Switch state.
NOTE: As the test runs, the NVLD Switch should go from an OPEN state to
a CLOSED state and then return to OPEN when the test is complete.
Did the NVLD Switch operate as described above?

All

Yes

→ Refer to the INTERMITTENT CONDITION Symptom (Diagnos-

tic Procedure).
Perform POWERTRAIN VERIFICATION TEST VER - 5.

→ Go To 2

Turn the ignition off.
Disconnect the NVLD electrical harness connector.
Ignition on, engine not running.
Monitor the NVLD Switch state on the DRBIII

Connect a jumper wire between the (K107) NVLD Switch Signal circuit and the
(Z913) Ground circuit in the NVLD harness connector.
Does the Switch change from OPEN to CLOSED?

All

Yes

→ Replace the NVLD Assembly.

Perform POWERTRAIN VERIFICATION TEST VER - 5.

→ Go To 3

NOTE: Remove the jumper wire before continuing.

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TEST

ACTION

APPLICABILITY

Turn the ignition off.
Disconnect the C3 PCM harness connector.
Ignition on, engine not running.
Measure the voltage on the (K107) NVLD Switch Signal circuit in the NVLD
electrical harness connector.
Is the voltage above 5.3 volts?

All

Yes

→ Repair short to voltage in the (K107) NVLD Switch Signal circuit.

Perform POWERTRAIN VERIFICATION TEST VER - 5.

→ Go To 4

Turn the ignition off.
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 (K107) NVLD Switch Signal circuit from the NVLD
electrical harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

All

Yes

→ Go To 5

→ Repair the open in the (K107) NVLD Switch Signal circuit.

Perform POWERTRAIN VERIFICATION TEST VER - 5.

Measure the resistance between the (K107) NVLD Switch Signal circuit and the
(K106) NVLD Sol Control circuit in the NVLD electrical harness connector.
Is the resistance below 5.0 ohms?

All

Yes

→ Repair the short between the (K107) NVLD Switch Signal circuit

and the (K106) NVLD Solenoid Control circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.

→ Go To 6

Measure the resistance between the (Z913) Ground circuit and ground.
Is the resistance below 5.0 ohms?

All

Yes

→ Go To 7

→ Repair the open in the (Z913) Ground circuit.

Perform POWERTRAIN VERIFICATION TEST VER - 5.

All

Repair

Replace and program the Powertrain Control Module per Service
Information.
Perform POWERTRAIN VERIFICATION TEST VER - 5.

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P0453-NVLD PRESSURE SWITCH STUCK OPEN —

Continued

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