Idle Stop And Go Hyundai

Main Navigation

Advertisement
Social Connect
Resources
Our Brand Family
  • aftermarketNews website
  • AutoSuccess website
  • BodyShop Business website
  • Brake & Front End website
  • The Buzz EV News website
  • Counterman website
  • Engine Builder website
  • Fleet Equipment website
  • Motorcycle & Powersports News website
  • Professional Carwashing & Detailing website
  • TechShop website
  • Tire Review website
  • Tomorrow's Tech website
  • Tomorrow's Tech University website
  • Transmission Digest website
  • Underhood Service website
Import Car
Providing technical information and service resources to the import vehicle community
Asian

Hyundai Idle Stop And Go (ISG): Start/Stop Systems Are Here And Out Of Warranty

The Hyundai Idle Stop and Go (ISG) function is the automaker's start/stop system that found its way onto some 2012 models. ISG automatically switches off the engine when the car is at a standstill and starts it again as soon as the brake pedal is released. A lot has to happen for the engine to utilize ISG. Specific conditions with the engine, transmission and brake system all have to be met for the ISG system to function.

Andrew Markel
By Andrew Markel


The Hyundai Idle Stop and Go (ISG) function is the automaker’s start/stop system that found its way onto some 2012 models. ISG automatically switches off the engine when the car is at a standstill and starts it again as soon as the brake pedal is released.

Related Articles

A lot has to happen for the engine to utilize ISG. Specific conditions with the engine, transmission and brake system all have to be met for the ISG system to function.

Battery Conditions
When the engine stops, so does the alternator, so the battery must run the HVAC, infotainment and other systems with no disruption. Hyundai typically specifies an aggregated glass mat (AGM) battery for vehicles equipped with the ISG system. The correct AGM battery usually fits in the same location as a vehicle that is not equipped with an ISG system. Also, the BCI group size might be the same. The best way to order the correct replacement battery is to look at the old label for cold cranking amps (CCA) and reserve capacity (RC). The replacement battery should meet or exceed these specifications.

The ISG system also measures the health of the battery in two ways. First, it measures the battery’s state of charge (SOC) with a current and voltage sensor on the positive battery terminal. The temperature of the battery is measured with a sensor mounted on the positive battery terminal. If the battery is below 77% SOC, ISG will not work. And, if the battery temperature is below 35° F or above 133° F, the ISG will not shut down the engine. Also, if the system detects a crank that’s longer than two seconds, the ISG system will be deactivated.

Engine and Cabin Conditions
An ISG engine will not switch off the engine if it is too cold or hot, inside and outside. The coolant must reach 174° F so the engine can get to operating temperature as quickly as possible to reduce startup emissions. Coolant temperature is also critical for the passengers in the cabin. The system will also look at the ambient temperature sensor’s data.


The ISG system will work only when ambient temperatures are between 28 and 95 degrees. This is done for driver comfort so they are not freezing in winter or roasting on the hottest summer days. Under certain conditions, if the blower fan for the HVAC system is set to MAX or defrost, the ISG will not shut down the engine.

Brake Conditions
The ISG uses both the brake pedal position sensor’s information and the pressure transducer on the brake booster to perform an auto stop or start. The vacuum in the booster needs to be below -35kpa. The ISG will force a restart when the engine goes above -35kpa.

If there is not enough vacuum, the pedal will sink and the booster will not be available to produce enough assist if the driver needed to stop suddenly after the restart. Also, if the vehicle does not go faster than 5 mph after a stop/start event, the engine will not shut down again.

The yaw, lateral accelerometers and steering angle sensors are also used by the ISG system. If the car is stopped on a slope that is greater than 12 degrees uphill or downhill, the ISG system will not stop the engine. Also, if the steering angle sensor reads more than 180 degrees in either direction, it will not shut down the engine.

Code Conditions
The most common cause of ISG deactivation is the presence of codes stored in modules. Codes for sensors in the cooling, brake and battery systems will stop ISG operation. Also, codes for CAN bus communication will stop ISG operation because the ISG module needs to communicate with the ECM, Transmission and ABS modules.

Diagnostic Tips
1. If the engine has to perform a forced restart, the ISG light in the instrument cluster will flash for five seconds.
2. If you have to shut the hood with the engine running and are planning to go for a test drive, restart the vehicle with the key. The ISG system will not work if the hood is opened during the drive cycle. This is a safety feature to prevent a technician from being injured.
3. In some cases, if you are testing emissions monitors or testing the EVAP system, the ISG system will not work again until the scan tool is unplugged.

You May Also Like

Undercar

Are You Getting Enough Air?

If your airline can’t flow enough volume, you won’t maintain the proper pressure for correct air tool operation.

ImportCar Staff Writers
By ImportCar Staff Writers

Courtesy of TechShop by Eric Garbe

One of the biggest mistakes I’ve seen over the years starts with an auto technician being unhappy with the performance of his or her air impact wrench. To make matters worse, there’s always a certain aura surrounding this tool, and whomever owns the most powerful one in the shop holds sort of “bragging” rights over everyone else.Not only are technicians searching for the type of power that can break loose almost any bolt, but whether we admit it or not, there’s a competitive spirit in most of us that wants to have the most powerful impact in the shop.Then one of the local tool dealers strolls in with a brand-new impact wrench featuring all-kinds of earth-shattering torque and before you know it technicians are willing to make payments for the next six months with the hopes that their new tool will dethrone the top dog and break bolts loose without breaking a sweat. The unfortunate reality is that in most cases their new tool doesn’t live up to expectations. Even if it happens to work better than their old one, it’s probably still not at full capacity, a fact often unbeknownst to the owner.All air tools are designed to work with a specific amount of air pressure, and most of those we use for automotive repair are in the range of 90-100 pounds per square inch (psi). Just like an internal combustion engine produces maximum power and torque at a certain RPM range, your air tools are designed to operate at a specified psi and airflow in order to provide their designed speed and torque.This is where the wheels usually start to fall off the wagon. We’re often warned by tool dealers not to operate air tools at a pressure higher than they’re rated because it will cause accelerated wear, and perhaps sudden failure of the tool. Do we listen? Usually not. If the tool works and gets an extra boost from the higher psi in the shop, it’s all good, right? We’ve got work to do and no time to piddle around with the small details!We also know that the lower the pressure, the lower the power output of an air tool. We’ve all waited plenty of times for the air compressor to kick off at its upper pressure limit before we try to break loose that crank bolt. And we know what the pressure gauge on the shop compressor reads, with most of them being between 120-150 psi, so we figure we’ve got plenty of pressure. But alas, we’re disappointed when the crank bolt still doesn’t budge.The reality is that most likely your air tools are not getting the correct pressure and volume, and regardless of the pressure at the compressor, rarely are they subjected to higher-than-needed pressure. The key lies in static versus dynamic air pressure.Static pressure is the amount available in the line when nothing is operating. When you read the gauge on the compressor, it’s easy to think this is what your air tools are operating at, and if you were to check the pressure at the end of your air hose, you would see the same reading. But this is only the static pressure.

Read Full Article

More Asian Posts
Toyota Direct Injection? Port Injection? Why Not Both?

Port fuel injection and direct fuel injection systems each have their advantages and disadvantages.

By Andrew Markel
Mazda SkyActiv Engine Service Tips

These engines have been reliable, but there are four pattern failures you might see at your shop.

By Andrew Markel
Nissan Electro Hydraulic Steering

Nissan’s steering system is susceptible to driver-error. Here’s what to look for in these systems.

By Andrew Markel
Nissan Suspension Restoration

The shock or strut controls how the energy in the spring is absorbed and compressed.

By Andrew Markel

Other Posts

TSB Watch – Volkswagen: Top 10 Fixes For Popular VW Models

Every year, Volkswagen issues hundreds of Technical Service Bulletins (TSBs) covering everything from sunroof leaks to new oil specifications. TSBs are communication tools provided to help technicians address problems in the field and to expedite the repair process by arming them with brand-specific service information. Related Articles – VW 2.0 TSI Intake Manifold DTCs –

By Andrew Markel
ADAS Module Programming

Reflashing and reprogramming is a necessary service for repairing vehicles.

By Andrew Markel
Engineering Better Belt Systems

The belt drive system is working hardest when the engine is at idle.

By Andrew Markel
Spark Plug Fouling

Understanding why spark plugs get dirty.

By Andrew Markel