saab throttle body relearn

How to Perform a Throttle Relearn Procedure on Your Saab Vehicle

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How to Perform a Throttle Relearn Procedure on Your Saab Vehicle

Performing a throttle relearn, also known as a throttle body synchronization or idle relearn, is an important maintenance procedure for many Saab vehicles. Over time, the electronic throttle control system can lose its adaptive memory settings, leading to poor idle quality, rough running, hesitation on acceleration, and other drivability issues. Resetting the throttle body calibration allows the engine control module (ECM) to relearn the correct throttle position sensor settings.

This comprehensive guide will explain the throttle relearn procedure for popular Saab models, including the 9-3, 9-5, 9-7X, and others. It is intended for informational purposes only – please consult with a qualified Saab mechanic and refer to your vehicle’s service manual before attempting this procedure.

Symptoms Indicating a Throttle Relearn May Be Needed

  • Rough, unstable, or high idle
  • Engine stalling
  • Hesitation or stumbling on acceleration
  • Check engine light on with throttle body related fault codes
  • Reduced fuel efficiency
  • Uneven or jerky power delivery
  • Surging or hunting idle
  • Inconsistent engine response to accelerator pedal input

Common Reasons for Losing Throttle Calibration

The adaptive throttle position settings can be lost or corrupted for several reasons:

  • Disconnecting or replacing the battery
  • Performing an ECM reset
  • Clearing diagnostic trouble codes
  • Replacing the throttle body
  • Modifying the air intake or engine tune
  • Electrical issues such as corroded wiring or loose connections

If you have experienced any of these situations, it’s a good idea to perform a throttle relearn to restore proper operation. In some cases, a scan tool may directly prompt you that a relearn is required.

Safety Precautions

Before beginning the throttle relearn procedure, make sure to follow these important safety guidelines:

  1. Park your vehicle on a level surface, engage the parking brake, and ensure the transmission is in Park (automatic) or Neutral (manual).
  2. Turn off all electrical accessories and ensure nothing is plugged into the 12V power outlets.
  3. Do not touch or disturb the accelerator pedal during the relearn process. Any external input can cause the procedure to fail.
  4. Make sure the battery is fully charged and in good condition. Use a charger to maintain voltage if needed.
  5. Work in a well-ventilated area away from flammable materials since the engine will be running.
  6. Keep hands, clothing, tools, and other objects away from moving parts in the engine compartment.
  7. Allow the engine to cool before beginning work to avoid burns or injuries.
  8. Wear safety glasses and protective gloves.
  9. Have a fire extinguisher on hand.
  10. If you feel unsure or uncomfortable at any point, stop and consult a professional Saab mechanic for assistance.

General Throttle Relearn Process

While the exact steps can vary between specific Saab models and engine types, the general process for performing a throttle position sensor relearn is as follows:

  1. Switch the ignition on (key in position II) but do not start the engine. Make sure all accessories are off.
  2. Wait 10 seconds to allow the ECM to power up fully. You may hear some clicking noises from the throttle body during this time.
  3. Fully depress the accelerator pedal to the floor and release it completely. Perform this full range of motion 3-5 times in succession.
  4. Wait 7-10 seconds for the ECM to recalibrate the sensor values. Do not touch the pedal during this time.
  5. Start the engine and let it idle in Park for 3 minutes. The engine may run rough or fast at first but should gradually stabilize.
  6. Perform a road test, driving at various steady speeds and gently accelerating. Make sure to drive long enough for the transmission to shift through each gear. Avoid hard acceleration or high RPMs.
  7. If the symptoms persist, repeat the relearn procedure 2-3 more times. In rare cases, a manual throttle body cleaning or replacement may be required if the valve is physically sticking.

Some later model year Saab vehicles (2006+) may support an alternative relearn method via a compatible scan tool like the Tech 2:

  1. Connect the scan tool to the vehicle’s OBD-II port and power it on.
  2. Navigate to the Engine Control Module menu and select Throttle Actuator.
  3. Choose the Calibration or Relearn function and follow the on-screen prompts. The process will take 30-60 seconds.
  4. Once complete, restart the engine and perform a road test to confirm proper operation.

Not all Saab models support this option. Consult your service manual or a dealer to check if a scan tool relearn is available for your specific vehicle.

Model-Specific Relearn Tutorials

Here are some of the most common Saab models that may require a throttle body relearn, along with specific instructions and tips for each vehicle. Click on a model to jump to its detailed tutorial:

Saab 9-3 (2003-2011)

The second generation Saab 9-3 is prone to developing throttle body issues, especially after a battery disconnect or ECM reset. Performing a relearn can often restore proper operation.

To perform the procedure:

  1. Sit in the driver’s seat and close all doors. Insert the key into the ignition.
  2. Turn the key to the ON position (one click before START) without starting the engine. All dash lights should illuminate.
  3. Wait 30 seconds, then fully depress the accelerator pedal to the floor and release it quickly. Repeat this 5 times in succession.
  4. Wait 10 seconds for the ECM to recalibrate. Do not touch the pedal during this time.
  5. Start the engine and let it idle for 3 minutes. It may run rough or fast at first but should gradually stabilize.
  6. Take the 9-3 for a 10 minute test drive. Accelerate smoothly and drive at various steady speeds, making sure the transmission shifts through each gear.
  7. If the idle remains unstable or surges, repeat steps 1-6 after allowing the engine to cool down fully.

Tips:

  • 9-3 models with push-button start use the same procedure, just push the button without your foot on the brake to enter accessory mode.
  • If the check engine light comes on during the relearn with throttle-related fault codes, the throttle body may be faulty. Common codes include P0121, P0122, P0123, P0222, P0223, P1101, P1515, P2135.
  • The 9-3’s electronic throttle body is located on top of the engine, attached to the intake manifold. Over time, carbon deposits can accumulate on the throttle plate and housing, causing the valve to stick. If the relearn doesn’t resolve your issues, try cleaning the throttle body with throttle body cleaner spray.

Saab 9-5 (1997-2009)

The Saab 9-5 sedan and wagon use a drive-by-wire throttle system that may need to be relearned after battery or ECM issues. The procedure is straightforward:

  1. Get in the driver’s seat and close the door. Insert the key into the ignition.
  2. Turn the key to position II (ON) without starting the engine. The SID should light up.
  3. Wait 10 seconds, then fully press and release the accelerator pedal 3 times within 5 seconds.
  4. Wait another 10 seconds for the ECM to recalibrate. You may hear a slight clicking noise from the throttle body.
  5. Start the engine and let it idle for 2 minutes. Do not touch the gas pedal. The idle may be high at first.
  6. Perform a road test, driving normally for at least 10 minutes. Make sure the transmission shifts through each gear.
  7. If you still experience symptoms, repeat steps 1-6 after letting the engine cool down completely.

Tips:

  • If you have access to a Tech 2 scanner, you can perform the relearn through the TCS menu. Select “Throttle Body” then “Calibration”.
  • Early 9-5 models (1997-2001) may require a slightly different relearn procedure. Consult your owner’s manual or a Saab forum for details.
  • A rough or unstable idle after the relearn can indicate a vacuum leak. Check the rubber intake boots for cracks or loose clamps.

Saab 9-7X (2005-2009)

The Saab 9-7X SUV shares its platform with the Chevrolet Trailblazer and GMC Envoy. As such, it uses a similar throttle body relearn procedure:

  1. Start with the engine off and the transmission in Park.
  2. Turn the ignition key to the ON position without starting the engine.
  3. Wait 3 seconds, then fully depress and release the accelerator pedal 5 times within 5 seconds.
  4. Wait 7 seconds for the relearn to complete. You will hear a click from the throttle body when it’s done.
  5. Start the engine and let it idle in Park for 3 minutes. The idle will start high and gradually come down.
  6. Drive the vehicle for 5-10 minutes, using various throttle positions. Let the transmission shift through each gear.
  7. Repeat the process if you still notice symptoms.

Tips:

  • The 9-7X uses a cable-operated throttle body, unlike the drive-by-wire setup on other Saab models. However, it still has an electronic throttle position sensor that can become uncalibrated.
  • If the throttle body is sticking or clogged with carbon deposits, the relearn may not be successful. Try cleaning the throttle plate and housing with throttle body cleaner spray.
  • The 9-7X’s ECM is very sensitive to low battery voltage. If you’ve recently had a dead battery, make sure it is fully recharged before attempting a relearn. Ideally, use a battery charger to maintain 13-14V during the procedure.

Saab 900 (1994-1998)

The Saab 900 uses a traditional cable-operated throttle body, but its Trionic 5 engine management system can still benefit from a throttle position sensor relearn in some cases.

Here’s the process:

  1. Park the vehicle and turn the ignition key to the ON position without starting the engine.
  2. Wait 10 seconds, then press the accelerator pedal to the floor and release it fully. Do this 3 times in a row.
  3. Wait another 10 seconds for the ECM to recalibrate the sensor.
  4. Start the engine and let it idle for 60 seconds. The idle speed may be slightly high at first.
  5. Take the 900 for a 5 minute drive around the block. Accelerate smoothly and drive at various steady speeds.
  6. If the idle remains high or surges, repeat steps 1-5.

Tips:

  • The 900’s throttle position sensor is located on the throttle body, under the black plastic cover. If you suspect the sensor is faulty, you can test its resistance with a multimeter. It should read between 0.5-1.5 kΩ at idle and 3.5-4.5 kΩ at wide open throttle.
  • A dirty or sticky idle air control valve can cause symptoms similar to a bad TPS. Try cleaning the IAC valve and passages with carburetor cleaner if the relearn doesn’t help.
  • Worn throttle body bushings can introduce extra play in the throttle linkage, confusing the ECM. Inspect the throttle shaft for excessive movement and replace the bushings if needed.

Saab 9000 (1985-1998)

The Saab 9000, while a reliable car, can develop idling issues as it ages. Its LH-Jetronic fuel injection system uses a conventional throttle body with mechanical linkage, but the throttle position sensor may still need to be recalibrated occasionally.

Follow these steps:

  1. With the engine off, disconnect the negative battery cable. Wait 30 seconds, then reconnect it.
  2. Get in the driver’s seat and insert the key into the ignition. Turn it to the ON position without cranking the engine.
  3. Wait 5 seconds, then press and release the accelerator pedal 3 times.
  4. Wait another 5 seconds for the ECM to relearn the idle position.
  5. Start the engine and let it run for 2 minutes. Don’t touch the gas pedal.
  6. Perform a short test drive, accelerating gently through the gears. The idle should remain stable.
  7. If you still experience a rough idle or stalling, repeat the procedure.

Tips:

  • The 9000’s throttle position sensor is located on the right side of the throttle body, held in by two screws. Make sure these screws are tight and the sensor hasn’t shifted out of position.
  • Over time, the 9000’s idle air control valve can become clogged with carbon deposits, causing a rough or fluctuating idle. Remove the IAC valve and clean it with carburetor cleaner if the relearn doesn’t resolve your issues.
  • A failing coolant temperature sensor can also cause poor idle quality on the 9000. Check the sensor’s resistance with a multimeter – it should read around 2.5 kΩ at room temperature.

Final Words from Bossing Erwin

Performing a throttle body relearn is an important maintenance procedure for many Saab models. By resetting the electronic throttle control system’s adaptive memory, you can restore proper idle quality, throttle response, and overall driveability.

The exact relearn process can vary between different engines and model years, so it’s important to consult your owner’s manual or a Saab forum for specific instructions. In general, the procedure involves turning the ignition on and depressing the accelerator pedal several times in quick succession, followed by an idle period and a road test drive.

If the relearn procedure doesn’t resolve your issues, there may be an underlying problem with the throttle body, accelerator pedal, wiring, or ECM. Have these components diagnosed by a qualified Saab technician.