Source reference 2000-09-01

Manufacturer communication — 2000 GMC YUKON

Reporter type: Manufacturer

Vehicles as recorded

2000 GMC YUKON This vehicle's overview →
2000 GMC YUKON XL This vehicle's overview →

What the manufacturer’s document says

fault and correction ・ names this vehicle

Applies to

The affected models include the 2000 GMC Yukon 2WD & 4WD and Yukon XL 2WD & 4WD.
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2000 GMC Yukon 2WD & 4WD and Yukon XL 2WD & 4WD

Fault

On 1998-2000 OnStar equipped vehicles there may be no response when the OnStar button is pressed.
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T h e re may not be a response when the OnStar button is p ressed on 1998-2000 OnStar equipped vehicles.
The OnStar VS-3B buttons may not operate and the telltale LED may not flash after the OnStar Center button or Emergency button is pressed; a DTC B2476 may also be present.
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In addition, the OnStar VS-3B buttons may not operate and the telltale LED may not flash after the OnStar Center button or E m e rgency button is pressed. A DTC B2476 also may be pre- sent in the system.

Finding the cause

Steps to confirm (in the document’s order)

With the ignition on, check for 7-10 volts between pin E6 and E1; if there is no voltage and the wire at the terminal is not shorted to ground, replace the VIU.
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2. Check to ensure Voltage of 7- 10 Volts between Pin E6 and E1. If there is no voltage here and the wire at terminal E^ is not shorted to ground, Replace the VIU.
Back probe the blue VIU connector between terminals E4 and E1: there should be no voltage with the system on and no buttons pressed.
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3. Back probe the blue VIU connector for Vo l t a g e between terminals E4 and E1. There should be no voltage when the system is On and no buttons are depre s s e d .
Press and hold the Call Answer/End button: the voltage should be 0.33 volts +/- 10%.
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4. Press and hold the Call Answer/End button. The Voltage should be 0.33 volts +/- 10%.
Press and hold the OnStar Services button: the voltage should be 1.3 volts +/- 10%.
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5. Press and hold the OnStar Services button. The voltage should be 1.3 Volts +/- 10%.
Press and hold the Emergency button: the voltage should be 2.2 volts +/- 10%.
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7. Press and hold the Emergency button. The voltage should be 2.2 Volts +/- 10%

Correction

Repair

If the readings do not agree with the specified values, replace the button assembly; if it is a mirror mounted button assembly, replace the mirror.
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If the readings do not agree with the specified values, the button assembly must be replaced. If this is a mirror mounted button assembly, the mirror must be re p l a c e d .

Caution

In these cases use OnStar Diagnostic Table DT3 (OnStar Button Assembly Test), but the values given in step 7 of that test are incorrect.
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If any of these conditions are pre s e n t , refer to the OnStar Diagnostic Table DT3 (OnStar Button Assembly Test). However, the values given in step 7 of the test are incorre c t .

What is needed

Parts and materials: VIU (when there is no voltage between Pin E6 and E1 and the wire at the terminal is not shorted to ground)
OnStar button assembly (when the readings do not agree with the specified values)
Mirror (when the button assembly is mirror mounted)
Labor time: Not stated
Special tools: Not stated
Scan tool: Not stated

Only what the technical documents state. "Not stated" does not mean not needed.

Compiled by reading the full text of the document; each point stands on the passage shown. Check the document itself, linked below, before working on a vehicle.

Stated content

Communication summary
OnStar ボタンのテスト 2000 GMC Yukon 2WD & 4WD および Yukon XL 2WD & 4WD 1998-2000 の OnStar 装着車で、OnStar ボタンを押しても応答がないことがある。さらに、OnStar VS-3B のボタンが作動せず、OnStar Center ボタンまたは Emergency ボタンを押した後にテルテール LED が点滅しないことがある。システムに DTC B2476 が入っていることもある。これらの状態のいずれかがある場合は、OnStar Diagnostic Table DT3（OnStar Button Assembly Test）を参照する。ただし、このテストの手順 7 に示されている値は誤っている。 2. ピン E6 と E1 の間の電圧が 7- 10 ボルトであることを確認する。ここに電圧がなく、端子 E^ の配線がアースにショートしていない場合は、VIU を交換する。 3. 青色の VIU コネクターの端子 E4 と E1 の間の電圧をバックプローブで測る。システムがオンでどのボタンも押されていないときは、電圧がないはずである。 4. Call Answer/End ボタンを押し続ける。電圧は 0.33 ボルト +/- 10% のはずである。 5. OnStar Services ボタンを押し続ける。電圧は 1.3 ボルト +/- 10% のはずである。 7. Emergency ボタンを押し続ける。電圧は 2.2 ボルト +/- 10% のはずである。測定値が規定値と合わない場合は、ボタン ASSY を交換しなければならない。ミラーに取り付けられたボタン ASSY の場合は、ミラーを交換しなければならない。 Machine translation (unreviewed)
OnStar Button Test 2000 GMC Yukon 2WD & 4WD and Yukon XL 2WD & 4WD T h e re may not be a response when the OnStar button is p ressed on 1998-2000 OnStar equipped vehicles. In addition, the OnStar VS-3B buttons may not operate and the telltale LED may not flash after the OnStar Center button or E m e rgency button is pressed. A DTC B2476 also may be pre- sent in the system. If any of these conditions are pre s e n t , refer to the OnStar Diagnostic Table DT3 (OnStar Button Assembly Test). However, the values given in step 7 of the test are incorre c t . 2. Check to ensure Voltage of 7- 10 Volts between Pin E6 and E1. If there is no voltage here and the wire at terminal E^ is not shorted to ground, Replace the VIU. 3. Back probe the blue VIU connector for Vo l t a g e between terminals E4 and E1. There should be no voltage when the system is On and no buttons are depre s s e d . 4. Press and hold the Call Answer/End button. The Voltage should be 0.33 volts +/- 10%. 5. Press and hold the OnStar Services button. The voltage should be 1.3 Volts +/- 10%. 7. Press and hold the Emergency button. The voltage should be 2.2 Volts +/- 10% If the readings do not agree with the specified values, the button assembly must be replaced. If this is a mirror mounted button assembly, the mirror must be re p l a c e d .
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Source

Source: GM TechLink
Source reference: 2000-09-01
Received by source: 2000-09-01
Incident date: Unknown

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