<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="./twl_formatc.xsl"?>
<servinfo
releasenbr="1"
update="original"
id="mf6b10444ea4444cb352b48e35bcc46a"
><title
>P063A-GENERATOR VOLTAGE SENSE CIRCUIT</title><figure
figtype="2-column-portrait-no-fig-id"
id="b4e52bd6ced44f839ba7d69cf74afe25"
><graphic
graphicname="7a033931"
></graphic></figure><para
><ptxt
>For a complete wiring diagram <emph
>Refer to Section 8W</emph>.</ptxt></para><diagnostic
type="condition"
><condition
><spec
><list1
><item
><ptxt
><emph
>When Monitored:</emph></ptxt><para
><ptxt
>The engine running. The engine speed greater than 1157 RPM.</ptxt></para></item><item
><ptxt
><emph
>Set Condition:</emph></ptxt><para
><ptxt
>The PCM recognizes the alternator output voltage is less than the Battery feed circuit voltage. One trip failure. The Generator light will illuminate. The fault will be checked again on the next key
cycle.</ptxt></para></item></list1><table
><tgroup
xmlns:fo="http://www.w3.org/1999/XSL/Format"
xmlns:saxon="http://icl.com/saxon"
border-width.conditionality="retain"
font-size="7pt"
width="100%"
border-collapse="collapse-with-precedence"
table-omit-header-at-break="false"
border-width="1pt"
border-color="black"
border-style="solid"
space-after="6pt"
table-layout="fixed"
><table-column
column-number="1"
column-width="proportional-column-width(396)"
></table-column><thead
><row
><entry
valign="bottom"
align="center"
><ptxt
><emph
>Possible Causes</emph></ptxt></entry></row></thead><tbody
><row
><entry
valign="top"
align="left"
><ptxt
>EXCESSIVE RESISTANCE IN THE (A804) GENERATOR SENSE CIRCUIT</ptxt></entry></row><row
><entry
valign="top"
align="left"
><ptxt
>(A804) GENERATOR SENSE CIRCUIT SHORTED TO GROUND</ptxt></entry></row><row
><entry
valign="top"
align="left"
><ptxt
>GENERATOR</ptxt></entry></row><row
><entry
valign="top"
align="left"
><ptxt
>PCM</ptxt></entry></row></tbody></tgroup></table></spec><para
><ptxt
><emph
>Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. <extxref
document="SOFTLINK"
extrefid="0900000030"
>(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)</extxref>.</emph></ptxt></para></condition></diagnostic><diagnostic
type="test"
><?STEP 1------------------------------------------------------------------------------------------------------------------------------------------------------------------------------?><testgrp
><title
>Diagnostic Test</title><spec
><ptxt
><testno><emph>1.</emph></testno> <emph
>ACTIVE DTC</emph></ptxt></spec><attention3
name="NOTE"
><ptxt
>Inspect the vehicle for aftermarket accessories that may exceed the Generator System output.</ptxt></attention3><attention3
name="NOTE"
><ptxt
>The battery must be fully charged.</ptxt></attention3><attention3
name="NOTE"
><ptxt
>The Generator belt tension and condition must be checked before continuing.</ptxt></attention3><test1
><ptxt
>Ignition on, engine not running.</ptxt></test1><test1
><ptxt
>With a scan tool, select View DTCs.</ptxt></test1><test1
><ptxt
>Start the engine.</ptxt></test1><test1
><ptxt
>Allow the idle to stabilize.</ptxt></test1><test1
><ptxt
>With the scan tool, select View DTCs.</ptxt></test1><question
>Is the DTC Active at this time?</question><result
>Yes</result><action
><list1
><item
><ptxt
>Go To <intxref
refid="l649b1c9ab794c78ad50e0661632aea7"
>2</intxref></ptxt></item></list1></action><result
>No</result><action
><list1
><item
><ptxt
>Refer to the INTERMITTENT CONDITION Diagnostic Procedure.</ptxt></item><item
><ptxt
>Perform the POWERTRAIN VERIFICATION TEST. <extxref
document="SOFTLINK"
extrefid="0900000360"
>(Refer to 9 - ENGINE - STANDARD PROCEDURE)</extxref><symbol
name="SKIP"
></symbol></ptxt></item></list1></action></testgrp><?STEP 2------------------------------------------------------------------------------------------------------------------------------------------------------------------------------?><testgrp
id="l649b1c9ab794c78ad50e0661632aea7"
><spec
><ptxt
><testno><emph>2.</emph></testno> <emph
>EXCESSIVE RESISTANCE IN THE (A804) GENERATOR SENSE CIRCUIT</emph></ptxt></spec><figure
figtype="1-column-portrait-no-fig-id"
id="bb8304b69f9f4f54b29010abb3e3b362"
><graphic
graphicname="7a033621"
></graphic></figure><test1
><ptxt
>Turn the ignition off.</ptxt></test1><test1
><ptxt
>Disconnect the Generator harness connector.</ptxt></test1><test1
><ptxt
>Disconnect the C1 PCM harness connector.</ptxt></test1><test1
><attention2
name="CAUTION"
><ptxt
>Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller
Special Tool #8815 to perform diagnosis.</ptxt></attention2></test1><test1
><ptxt
>Measure the resistance of the (A804) Generator Sense circuit from the Generator harness connector to the appropriate terminal of special tool #8815.</ptxt></test1><question
>Is the resistance below 5.0 ohms?</question><result
>Yes</result><action
><list1
><item
><ptxt
>Go To <intxref
refid="o916f59b597b423aa13b8fd953a97159"
>3</intxref></ptxt></item></list1></action><result
>No</result><action
><list1
><item
><ptxt
>Repair the excessive resistance in the (A804) Generator Sense circuit.</ptxt></item><item
><ptxt
>Perform the POWERTRAIN VERIFICATION TEST. <extxref
document="SOFTLINK"
extrefid="0900000360"
>(Refer to 9 - ENGINE - STANDARD PROCEDURE)</extxref> <symbol
name="skip"
></symbol></ptxt></item></list1></action></testgrp><?STEP 3------------------------------------------------------------------------------------------------------------------------------------------------------------------------------?><testgrp
id="o916f59b597b423aa13b8fd953a97159"
><spec
><ptxt
><testno><emph>3.</emph></testno> <emph
>(A804) GENERATOR SENSE CIRCUIT SHORTED TO GROUND</emph></ptxt></spec><figure
figtype="1-column-portrait-no-fig-id"
id="id2eb1b24da94e259039906508f10291"
><graphic
graphicname="7a033622"
></graphic></figure><test1
><ptxt
>Measure the resistance between ground and the (A804) Generator Sense circuit at the Generator harness connector.</ptxt></test1><question
>Is the resistance below 100 ohms?</question><result
>Yes</result><action
><list1
><item
><ptxt
>Repair the short to ground in the (A804) Generator Sense circuit.</ptxt></item><item
><ptxt
>Perform the POWERTRAIN VERIFICATION TEST. <extxref
document="SOFTLINK"
extrefid="0900000360"
>(Refer to 9 - ENGINE - STANDARD PROCEDURE)</extxref></ptxt></item></list1></action><result
>No</result><action
><list1
><item
><ptxt
>Go To <intxref
refid="la1f403c8a104fceb3adb73b06ff2ab8"
>4</intxref><symbol
name="SKIP"
></symbol></ptxt></item></list1></action></testgrp><?STEP 4------------------------------------------------------------------------------------------------------------------------------------------------------------------------------?><testgrp
id="la1f403c8a104fceb3adb73b06ff2ab8"
><spec
><ptxt
><testno><emph>4.</emph></testno> <emph
>GENERATOR OPERATION</emph></ptxt></spec><figure
figtype="1-column-portrait-no-fig-id"
id="ife4d6a4c05b488da2a3d4074915d1ff"
><graphic
graphicname="7a033619"
></graphic></figure><test1
><ptxt
>Connect the C1 PCM harness connector.</ptxt></test1><test1
><ptxt
>Using a 12-volt test light connected to ground, probe the (K125) Generator Field Control circuit in the Generator Field harness connector.</ptxt></test1><test1
><ptxt
>Ignition on, engine not running.</ptxt></test1><test1
><attention3
name="NOTE"
><ptxt
>The DTC needs to be cleared before actuating the Solenoid, if the DTC is not cleared, the Solenoid may not be allowed to actuate.</ptxt></attention3></test1><test1
><ptxt
>With a scan tool, actuate the Generator Field Driver.</ptxt></test1><question
>Does the test light illuminate brightly and flash on and off?</question><result
>Yes</result><action
><list1
><item
><ptxt
>Replace the Generator.</ptxt></item><item
><ptxt
>Perform the POWERTRAIN VERIFICATION TEST. <extxref
document="SOFTLINK"
extrefid="0900000360"
>(Refer to 9 - ENGINE - STANDARD PROCEDURE)</extxref></ptxt></item></list1></action><result
>No</result><action
><list1
><item
><ptxt
>Go To <intxref
refid="e74e8a7bb13442fe829f9d08b8c063d7"
>5</intxref><symbol
name="SKIP"
></symbol></ptxt></item></list1></action></testgrp><?STEP 5-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------?><testgrp
id="e74e8a7bb13442fe829f9d08b8c063d7"
><spec
><ptxt
><testno><emph>5.</emph></testno> <emph
>PCM</emph></ptxt></spec><attention3
name="NOTE"
><ptxt
>Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.</ptxt></attention3><test1
><ptxt
>Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.</ptxt></test1><question
>Were there any problems found?</question><result
>Yes</result><action
><list1
><item
><ptxt
>Repair as necessary.</ptxt></item><item
><ptxt
>Perform the POWERTRAIN VERIFICATION TEST. <extxref
document="SOFTLINK"
extrefid="0900000360"
>(Refer to 9 - ENGINE - STANDARD PROCEDURE)</extxref></ptxt></item></list1></action><result
>No</result><action
><list1
><item
><ptxt
>Replace and program the Powertrain Control Module per Service Information.</ptxt></item><item
><ptxt
>Perform the POWERTRAIN VERIFICATION TEST. <extxref
document="SOFTLINK"
extrefid="0900000360"
>(Refer to 9 - ENGINE - STANDARD PROCEDURE)</extxref><symbol
name="SKIP"
></symbol></ptxt></item></list1></action></testgrp></diagnostic></servinfo>