Preliminary Checks

NOTE: Prior to performing any diagnostics or engine related testing, perform all preliminary tests first. Set all adjustments to specifications listed on vehicle emissions decal.

On all vehicles, check idle speed with automatic transmissions in "DRIVE" position (if equipped) and ensure correct idle RPM is obtained. Ensure ignition timing is set to proper specification.
Disconnect throttle switch harness connector, exhaust gas sensor connector and install a 2500 ohm resistor into the temperature sensor circuit with sensor disconnected.
Confirm acceptable CO level by ensuring that Red LED light flashes in Mode 2.
Maintain idle speed at middle engine speed (approximately 2000 RPM).
On Pathfinder/Pickup (VG30i), while in Mode 2 of diagnostics, Red and Green inspection lights should flash simulta- neously 5 or more times in 10 seconds. On Pathfinder/Pickup (Z24i) models, Red and Green inspection lights should flash simultaneously 7 or more times in 10 seconds while in Mode 2.

Perform an idle speed switch test. Idle speed should increase to the amount specified in the IDLE SWITCH SPEED INCREASES chart when idle speed switch is turned from "OFF" to "ON" position. If idle is not as specified, adjust accordingly.

IDLE SWITCH SPEED INCREASES

Model

A/T In Neutral

M/T

RPM+ or -

VG30i

250

150

Z24i

⁽¹⁾

⁽¹⁾	At 1600 RPM, when idle switch is activated from off to on, speed should increase up to 2150 RPM. When turned from on to off, speed should decrease as low as 1350 RPM.

Perform a test drive to evaluate the effectiveness of any adjustments that may have been made. If any driveability problems still exist, see SYSTEM INSPECTION CHART or DRIVEABILITY INSPECTION CHART.
Perform the Mode 3 Self-Diagnosis, then the Mode 4 Switch On/Off Test Diagnosis and a test drive to determine if intermittent problems exist. Write down any diagnostic codes may which appear.
A test drive to determine if any remaining problems exist.
If the results of the test drive are unsatisfactory (codes are presented), refer to the applicable SYSTEM INSPECTION CHART. For driveability problems, see applicable DRIVEABILITY INSPECTION CHART.
After all replacements and/or repairs are completed, test drive the vehicle to evaluate the vehicles performance after the diagnosis and repair procedure is completed.