Info - Product Enhancements to Improve Slow/No Start Conditions in Extreme Cold Weather

Several improvements were put into production during the 1999-2000 model years to improve slow or no start conditions at temperatures below -23.3°C (-10°F). Slow/no-start conditions may be aggravated by the length of time the vehicle sits in this type of climate. When diagnosing such conditions, verify the vehicle has been equipped with the improvements noted below.

In extreme cold temperatures, four components are affected which together may cause hard starting.

Each of the revisions listed below provide an incremental improvement to cold weather starting. To effectively improve the cold start ability of the vehicle, you must confirm which of the revisions are already present to prevent duplicating the repair.

Spark Plugs

If the vehicle has been brought in with a no start concern, replace the spark plugs with NGK Iridium plugs (GM P/N 91175704), even if the plugs are already that type. The no start condition and resultant rich fuel mixture may have fouled the plugs beyond useful service. If the vehicle has a slow start concern, verify that NGK Iridium plugs are installed by examining one plug. If they are not the Iridium type, replace the spark plugs following the procedure in the 1999/2000 Service Manual. Please inform and write-in the customer's Owners Manual the brand, type and P/N of the new design spark plugs so that the customer will not deviate from this specific plug at maintenance time.

Powertrain Control Module (PCM)

For model year 1999 and later, U.S. and Canadian dealers have the capability of reprogramming the PCM. When performing this procedure, you will need a Tech 2 scan tool and a Techline terminal. The Techline terminal must be a minimum of a T7. For the 1999 Tracker, you must have TIS 2000 software with CD #20/21or later. For the 2000 Tracker, you must have TIS 2000 software with CD #25 or later.

1. Open the TIS 2000 software application from the Techline terminal.
2. From the Application Selection screen, select "Service Programming System". The "Select Diagnostic Tool and Programming Process" screen should appear.
3. Select "Pass Thru".
4. Select "Reprogram ECU" or "Replace and Reprogram ECU".
5. Select either "Vehicle" or "Off Board Programming Adapter (OBPA)".
6. If your selections are correct, press the "Next" key.
7. At the "Connect Diagnostic Tool/Determine Vehicle" screen, enter the correct information until the "Next" key is highlighted then click "Next".
8. Turn the ignition ON.
9. Follow the directions on the "Connect Diagnostic Tool" screen, then click "Next". The "Validate Vehicle Identification Number" screen should appear.
10. The correct Vehicle Identification Number (VIN) may appear. If not, enter the correct VIN.
11. Select "Next" and an option screen will appear. Ensure that all the entered information is correct. If not, enter the correct information.
12. The "Calibration Selection" screen should appear. Verify the current calibrations with the selected calibrations.
13. A summary screen will appear. If correct, enter "Next".
14. The "Program Controller/Programming Complete" screen will appear when the programming is complete. Click on "Close".
15. Turn OFF the ignition for 30 seconds to reset the PCM.
16. Start the vehicle and let the vehicle idle for two minutes while observing the operation of the vehicle.
17. If the vehicle is operating normally, the programming is complete. If the vehicle will not start or does not idle normally, repeat the "PCM Reprogramming Pass Thru Procedure".

Battery

Beginning with the 2000 model year, battery size was increased to 600CCA. If the customer's vehicle is equipped with the 550CCA battery, you may upgrade the vehicle to the larger style. Increasing the battery size will give the vehicle a slightly higher cranking speed and more reserve capacity in extremely cold weather.

Starter Motor

Approximately April, 1999, a revised starter motor went into production. Check the customer's vehicle to verify that the revised starter motor is installed. The starter type can be identified by the placard on the motor body. If the two digit code at the right side top of the starter label is A2 or M2, the vehicle is equipped with the old style starter. Replace as indicated in the chart below following the procedure in the 1999/2000 Service Manual.

The following two recommendations will aid in the cold weather starting performance of the vehicle. Please note that the following should be considered customer pay items and the cost of these items are not covered under the terms of the General Motors New Car Warranty. If the customer elects to have the Engine Block Heater dealer installed, it will be covered for repair for the duration of the vehicle warranty.

Oil Recommendations

In extreme cold weather, it is advisable to use fully synthetic SAE 5W-30 or 0W-30 oil which display the API Certification Mark, "Starburst Symbol", as noted in the Owner's Manual. Synthetic oils in recommended viscosity grades should carry the API Certification Mark. When temperatures fall below -17°C (0°F), engine oil thickens to the point that during a cold start it creates some additional resistance that the starting system must overcome. Synthetic motor oil stays easily flowable at low temperatures and will aid in the efficient starting of this engine. The use of an SAE 5W-30 fully synthetic oil will not necessitate any seasonal changing and can remain in this engine when outside temperatures reach in excess of 38°C (100°F). If an SAE 0W-30 oil is used (the best choice for extremely cold weather), it can remain in the engine with outside temperatures of up to but not in excess of 38°C (100°F). While the use of these oils is not a requirement, your customers should be informed that they provide improved flow characteristics that will benefit cold starting and the lubrication of this vehicle.

Engine Block Heater

An engine block heater is available as a dealer installed accessory. If the vehicle is parked in an area where an electrical outlet is present, this accessory will provide greatly assisted cold weather starting ability. The use of an engine block heater when the temperature is below freezing will prevent the thickening of engine oil, providing greater lubrication at start up and easier starts. This accessory provides the most improvement in cold starting ability but may be impractical depending on the overnight location of the vehicle.

Important: Vehicles sold in Canada are equipped with an engine block heater. Refer to Canadian Campaign Number 99002 for 1999 models. Block heaters are included on 2000 models with RPO Z49.

Conserving Battery Power

You may also review some common sense items with your customer. When starting the vehicle in extreme cold, you can conserve battery power by making sure that all electrical accessories (radio, blower, wipers, etc) are turned off before attempting to start the vehicle.

Parts are currently available from GMSPO.