Engine Electrical Devices: Other Suzuki XL7 I

Heated Oxygen and Oxygen Sensor Notice

Silicon Contamination of Heated Oxygen Sensors Notice

ECM Function

The ECM can supply 5 volts or 12 volts to the various sensors or switches. This is done through pull-up resistors to the regulated power supplies within the ECM. In some cases, even an ordinary shop voltmeter will not give an accurate reading because the resistance is too low. Therefore, a DMM with at least 10 megaohms input impedance is required in order to ensure accurate voltage readings.

The ECM controls the output circuits by controlling the ground or the power feed circuit through the transistors or a device called an output driver module.

EEPROM

The electronically erasable programmable read only memory (EEPROM) is a permanent memory that is physically part of the ECM. The EEPROM contains program and calibration information that the ECM needs in order to control the powertrain operation.

Special equipment, as well as the correct program and calibration for the vehicle, are required in order to reprogram the ECM.

Theft Deterrent System Frequency Code Programming

This vehicle is equipped with a theft deterrent system which interfaces with the ECM. If the ECM is replaced, program the new ECM with the frequency code of the theft deterrent module that is currently on the vehicle. The vehicle will not start until this procedure is completed.

KS Module

The ECM employs an internal integrated circuit to continuously monitor the knock control evaluation circuit. The knock sensor (KS) module contains the circuitry that allows the ECM to utilize the knock sensor (KS) signals and diagnose the KS sensors and circuitry. If the ECM detects a fault in the ability of the KS module to sample these signals, a DTC sets.

Data Link Connector (DLC)

The data link connector (DLC) is a 16-pin connector that provides the technician a means of accessing serial data for aid in the diagnosis. This connector allows the technician to use a scan tool in order to monitor the various serial data parameters, and display the DTC information. The DLC is located inside of the drivers compartment, underneath the dash.

Malfunction Indicator Lamp (MIL)

The malfunction indicator lamp (MIL) is inside of the instrument panel cluster (IPC). The MIL is controlled by the ECM and illuminates when the ECM detects a condition that affects the vehicle emissions.

ECM Service Precautions

The ECM, by design, can withstand the normal current draws that are associated with the vehicle operations. However, care must be used in order to avoid overloading any of these circuits. When testing for opens or shorts, do not ground or apply voltage to any of the ECM circuits unless the diagnostic procedure instructs you to do so. These circuits should only be tested with a DMM.

Aftermarket (Add-On) Electrical And Vacuum Equipment

Aftermarket, add-on, electrical and vacuum equipment is defined as any equipment installed on a vehicle after leaving the factory that connects to the vehicles electrical or vacuum systems. No allowances have been made in the vehicle design for this type of equipment.

Add-on electrical equipment, even when installed to these strict guidelines, may still cause the powertrain system to malfunction. This may also include equipment not connected to the vehicle electrical system, such as portable telephones and radios. Therefore, the first step in diagnosing any powertrain condition is to eliminate all of the aftermarket electrical equipment from the vehicle. After this is done, if the problem still exists, the problem may be diagnosed in the normal manner.

Electrostatic Discharge (ESD) Damage

Note. In order to prevent possible electrostatic discharge damage to the ECM, DO NOT touch the connector pins on the ECM.

The electronic components that are used in the control systems are often designed to carry very low voltage. The electronic components are susceptible to damage caused by electrostatic discharge. Less than 100 volts of static electricity can cause damage to some electronic components. By comparison, it takes as much as 4,000 volts for a person to even feel the zap of a static discharge.

There are several ways for a person to become statically charged. The most common methods of charging are by friction and by induction. An example of charging by friction is a person sliding across a car seat.

Charging by induction occurs when a person with well insulated shoes stands near a highly charged object and momentarily touches ground. Charges of the same polarity are drained off leaving the person highly charged with the opposite polarity. Static charges can cause damage, therefore, it is important to use care when handling and testing electronic components.

Emissions Control Information Label

The underhood Vehicle Emissions Control Information Label contains important emission specifications and setting procedures. In the upper left corner is the exhaust emission information. This identifies the year, the manufacturing division of the engine, the displacement of the engine in liters, the class of the vehicle, and type of fuel metering system.

There is also an illustrated emission components and vacuum hose schematic.

This label is located in the engine compartment of this vehicle.

Basic Knowledge Required

A basic understanding of hand tools is necessary in order to effectively use this section of the article. You must be familiar with some of the basics of engine operation and electrical diagnosis in order to use this section of the article.

1. Basic electrical circuits-You should have an understanding of basic electricity and know the meaning of voltage (volts), current (amps), and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire, and you should be able to identify a shorted or open circuit by using a DMM. You should be able to read and understand a wiring diagram.
2. Use of digital multimeter-You should be familiar with the DMM, particularly the essential tool. You should be able to use the meter in order to measure the voltage (volts), the resistance (ohms), the current (amps), intermittents (min/max), and frequency (Hertz).
3. Use of circuit testing tools-You should not use a test lamp to diagnose the engine controls system unless you are specifically instructed to do so. You should know how to the use jumper wires in order to test the components and allow the DMM readings without damaging the terminals. You should know how to use the J 35616 connector test adapter kit and use the kit whenever the diagnostic procedures call for front probing any connector.

Throttle Body Relearn Procedure

The engine control module (ECM) stores values that include the lowest possible throttle position (TP) sensor positions-0 percent, the rest positions-7 percent, and the return rate of both springs. These values will only be erased or overwritten if the ECM is reprogrammed or if a throttle body relearn procedure is performed. Observe, if the battery is disconnected, the ECM will immediately perform a throttle body relearn procedure when the ignition is turned ON.

A throttle body relearn procedure is performed anytime the ignition is turned ON, with the engine OFF for longer than 29 seconds when the following conditions have been met

1. The engine speed is less than 40 RPM.
2. The vehicle speed is 0 km/h (0 mph).
3. The engine coolant temperature (ECT) is between 5-85°C (41-185°F).
4. The intake air temperature (IAT) is between than 5-60°C (41-140°F).
5. The accelerator pedal position (APP) sensor angle is less than 14.9 percent.
6. The ignition 1 voltage is more than 10 volts.

After 29 seconds, the ECM commands the throttle plate from the rest position to full closed, then to around 10 percent open. This procedure takes about 6-8 seconds. If any faults occur in the throttle actuator control (TAC) system, a DTC sets. At the start of this procedure, the scan tool TAC Learn Counter parameter should display 0, then count up to 11 after the procedure is completed. If the counter did not start at 0, or if the counter did not end at 11, a fault has occurred and a DTC should set.

TAC System Default Actions/Reduce Power Modes

There are 2 reduce power modes that the engine control module (ECM) can default to if an error is detected in the throttle actuator control (TAC) system. If an accelerator pedal position (APP) sensor 1 or APP sensor 2 circuit fault, throttle position (TP) sensor 2 circuit fault, or if a TP sensor 1 circuit fault is detected with some APP angle, the ECM goes into one of the 2 reduce power modes. In this mode, the engine torque is limited so that the vehicle cannot reach speeds of more than 100 km/h (60 mph). The ECM remains in this reduce power mode during the entire ignition cycle even if the fault is corrected.

If there is a condition with the throttle actuator control circuits, throttle actuator command vs actual position fault, return spring check fault, or a TP sensor 1 circuit fault, the ECM goes into the other reduce engine power mode. In this mode, the engine speed is limited to 2,500 RPM and the 3-6 fuel injectors are randomly turned OFF. At this time the Reduced Power indicator is commanded ON. The ECM remains in the reduce power mode during the entire ignition cycle even if the fault is corrected. Observe, if a TP sensor 1 or throttle actuator control circuit fault is present at the time the vehicle is at idle, with no accelerator pedal angle, the engine may stall.

Scheme 72

Scheme 73

1. Disconnect the engine wiring harness electrical connector (4) from the engine coolant temperature (ECT) sensor.
2. Remove the ECT sensor.

Scheme 74

Scheme 75

1. Install the ECT sensor. Tightening torque Tighten the sensor to 22 N.m (16 lb ft) .
2. Connect the engine wiring harness electrical connector (4) to the ECT sensor.

Scheme 76

Scheme 77

1. Remove the air cleaner outlet duct. Refer to «REMOVAL PROCEDURE»(ref-268436-S29502210142007102300000) .
2. Disconnect the engine wiring harness electrical connector from the mass air flow (MAF)/intake air temperature (IAT) sensor.
3. Remove the MAF/IAT sensor screws.
4. Remove the MAF/IAT sensor from the air cleaner assembly.
5. Remove the MAF/IAT sensor seal.

Scheme 78

Scheme 79

1. Install the MAF/IAT sensor seal to the MAF/IAT sensor.
2. Install the MAF/IAT sensor to the air cleaner assembly. CAUTION: Refer to «FASTENER NOTICE»(ref-268407-S42682275612007102300000) .
3. Install the MAF/IAT sensor screws. Tightening torque Tighten the screws to 4 N.m (35 lb in) .
4. Connect the engine wiring harness electrical connector to the MAF/IAT sensor.
5. Install the air cleaner outlet duct. Refer to «INSTALLATION PROCEDURE»(ref-268436-S38012727722007102300000) .

Scheme 80

Scheme 81

1. Remove the fuel injector sight shield, if necessary. Refer to «REMOVAL PROCEDURE»(ref-268436-S19439002942007102300000) .
2. Disconnect the engine wiring harness electrical connector (3) from the heated oxygen sensor (HO2S) electrical connector (2).
3. Remove the HO2S electrical connector retainer from the camshaft cover.
4. Remove the HO2S (1) from the exhaust manifold.

Engine Control Module Programming and Setup

The following service procedures require either a programming or a setup event performed for a complete repair.

ECM Reprogramming

1. If the ECM needs to be reprogrammed, refer to «SERVICE PROGRAMMING SYSTEM (SPS)»(ref-268408-S26236429192007102300000) .
2. Engine Oil Life Remaining-When available, use a scan tool to reset the Engine Oil Life Remaining back to the original percentage recorded before the module was reprogrammed.