Nissan Maxima Service and Repair Manual: Ignition signal
Description
The ignition signal from the ECM is sent to and amplified by the power
transistor. The power transistor turns
ON and OFF the ignition coil primary circuit. This ON/OFF operation induces the
proper high voltage in the coil
secondary circuit.
Component Function Check
1.INSPECTION START
Turn ignition switch OFF, and restart engine.
2.CHECK IGNITION SIGNAL FUNCTION
With CONSULT
- Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT.
- Check that each circuit produces a momentary engine speed drop.
3.CHECK IGNITION SIGNAL FUNCTION
Without CONSULT

- Let engine idle.
- Read the voltage signal between ECM harness connectors.

NOTE:
The pulse cycle changes depending on rpm at idle.
Diagnosis Procedure
1.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I

- Turn ignition switch OFF, wait at least 10 seconds and then turn it ON.
- Check the voltage between ECM harness connector and
ground.

2.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II

- Turn ignition switch OFF.
- Disconnect condenser harness connector.
- Turn ignition switch ON.
- Check the voltage between condenser harness connector and
ground.

3.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III
- Turn ignition switch OFF.
- Disconnect IPDM E/R harness connector.
- Check the continuity between IPDM E/R harness connector and
condenser harness connector.
- Also check harness for short to ground and short to power.

4.CHECK CONDENSER GROUND CIRCUIT FOR OPEN AND SHORT
- Turn ignition switch OFF.
- Check the continuity between condenser harness connector and
ground.
- Also check harness for short to power.

5.CHECK CONDENSER
6.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-V

- Reconnect all harness connectors disconnected.
- Disconnect ignition coil harness connector.
- Turn ignition switch ON.
- Check the voltage between ignition coil harness connector and
ground.

7.CHECK IGNITION COIL GROUND CIRCUIT FOR OPEN AND SHORT
- Turn ignition switch OFF.
- Check the continuity between ignition coil harness connector and ground.
- Also check harness for short to power.

8.CHECK IGNITION COIL OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
- Disconnect ECM harness connector.
- Check the continuity between ignition coil harness connector and
ECM harness connector.
- Also check harness for short to ground and short to power.

9.CHECK IGNITION COIL WITH POWER TRANSISTOR
10.CHECK INTERMITTENT INCIDENT
Component Inspection (Ignition Coil with Power Transistor)
1.CHECK IGNITION COIL WITH POWER TRANSISTOR-I

- Turn ignition switch OFF.
- Disconnect ignition coil harness connector.
- Check resistance between ignition coil terminals as per the
following.

2.CHECK IGNITION COIL WITH POWER TRANSISTOR-II
CAUTION:
Perform the following procedure in a place with no combustible objects and good
ventilation.
- Turn ignition switch OFF.
- Reconnect all harness connectors disconnected.
- Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
Do not use CONSULT to release fuel pressure, or fuel pressure applies again
during the following procedure.
- Start engine.
- After engine stalls, crank it two or three times to release all
fuel pressure.
- Turn ignition switch OFF.
- Remove all ignition coil harness connectors to avoid the
electrical discharge from the ignition coils.
- Remove ignition coil and spark plug of the cylinder to be checked.
Refer to EM-42, "Removal and Installation
(LH)" (LH) or EM-42, "Removal and Installation (RH)" (RH).
- Crank engine for 5 seconds or more to remove combustion gas in the
cylinder.
- Connect spark plug and harness connector to ignition coil.
- Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 -
0.66 in) between the edge of the spark plug and grounded metal
portion as shown in the figure.
- Crank engine for about three seconds, and check whether spark
is generated between the spark plug and the grounded metal
portion.

Spark should be generated.
CAUTION:
- Never place the spark plug and the ignition coil within 50
cm (19.7 in) each other. Be careful not to get an electrical
shock while checking, because the electrical discharge
voltage becomes 20 kV or more.
- It might damage the ignition coil if the gap of more than 17 mm
(0.66 in) is made.
NOTE:
When the gap is less than 13 mm (0.52 in), a spark might be generated even if
the coil is malfunctioning.
Component Inspection (Condenser)
1.CHECK CONDENSER

- Turn ignition switch OFF.
- Disconnect condenser harness connector.
- Check resistance between condenser terminals as per the following.

Description
*: ECM determines the start signal status by the signals of engine speed and
battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is
t ...
Description
The Malfunction Indicator Lamp (MIL) is located on the combination
meter.
The MIL will illuminate when the ignition switch is turned ON without
the engine running. This is a bu ...
Other materials:
Basic inspection
INSPECTION AND ADJUSTMENT
Operational Check
DESCRIPTION
The purpose of the operational check is to check that the individual system
operates normally.
Conditions: Engine running at normal operating temperature
INSPECTION PROCEDURE
1.CHECK MEMORY FUNCTION
Start the engine.
Operate the t ...
Chassis and Body Maintenance
Brake lines and cables:
Visually inspect for proper installation. Check for
chafing, cracks, deterioration, and signs of leaking.
Replace any deteriorated or damaged parts
immediately.
Brake pads, rotors, drums and linings:
Check for wear, deterioration and fluid leaks.
Replace any deteri ...
U1243 display unit
Description
Part name
Description
DISPLAY UNIT
Display image is controlled by the serial communication from AV
control unit.
Inputs the RGB image signal (RGB, RGB area and RGB
synchronizing) from AV control unit and the auxiliary image ...