<H1>DTC C0327</H1><A name=ss1-853460><A href="#ss1-853460">
<H5>Circuit Description</A></H5>
The transfer case shift control module has four encoder channels, P, C, A,
and B, which are supplied 5volts each. The four encoder channels each run
to a switch located inside the encoder/motor assembly. When a particular encoder
channel is active the switch is closed and 5volts flows through the
encoder signal return circuit. If the module wants to request motor position a
low side driver pulls the voltage low on the encoder signal return and the
corresponding channel circuit indicating motor position.</P>
The transfer case shift control module supplies 5volts on all encoder
channels, thus as these channels are pulled to ground, the module can interpret
the location of the transfer case shift position.</P>
This DTC detects an open, high resistance, or a short to voltage in the
encoder signal return circuit, or an open, high resistance, or short to voltage
in the encoder channel circuits.</P><A name=ss2-853460><A href="#ss2-853460">
<H5>Conditions for Running the DTC</A></H5>
<UL type=BULLET>
<LI>Ignition is ON.
<LI>System voltage is 9--18volts. </LI>[/list]<A name=ss3-853460><A
href="#ss3-853460">
<H5>Conditions for Setting the DTC</A></H5>
The transfer case shift control module reads back a high voltage when a low
voltage is expected, or low voltage when a high voltage is expected on the
encoder channel circuits, or the encoder signal return circuit.</P><A
name=ss4-853460><A href="#ss4-853460">
<H5>Action Taken When the DTC Sets</A></H5>
<UL type=BULLET>
<LI>All motor activity will stop.
<LI>All the transfer case shift control switch mode indicators will be commanded
OFF.
<LI>The SERVICE 4WD indicator will be latched on for the remainder of the
current ignition cycle.
<LI>If a new mode is requested while the DTC is present either current or
history, the indicator for the mode requested will flash for 15seconds and
then go out. </LI>[/list]<A name=ss5-853460><A href="#ss5-853460">
<H5>Conditions for Clearing the DTC</A></H5>
<UL type=BULLET>
<LI>The transfer case shift control module will clear the DTC if the condition
for setting the DTC no longer exists.
<LI>A history DTC will clear after 33consecutive ignition cycles without a
fault present.
<LI>History DTCs can be cleared using a scan tool. </LI>[/list]<A
name=ss6-853460><A href="#ss6-853460">
<H5>Test Description</A></H5>
The numbers below refer to the step numbers on the diagnostic table.</P>
- <A name=TD02>
<LI value=2>
Determines if two or more of the 5volts encoder signal circuits are
shorted together.</P><A name=TD03>
<LI value=3>
Checks for proper voltage on the four encoder signal circuits.</P><A
name=TD04>
<LI value=4>
Tests for a short to voltage, open, or high resistance on the encoder low
reference circuit.</P><A name=TD05>
<LI value=5>
Determines which encoder signal circuits are shorted together.</P><A
name=TD06>
<LI value=6>
Determines if any of the encoder signal circuits have an open, or high
resistance condition.</P><A name=TD07>
<LI value=7>
Determines if a binding shift detent lever shaft is causing the
DTC.</P></LI>
<TABLE width="100%" border=1>
<TBODY>
<TR>
<TH vAlign=bottom align=middle>
Step</P></TH>
<TH vAlign=bottom align=middle>
Action</P></TH>
<TH vAlign=bottom align=middle>
Value(s)</P></TH>
<TH vAlign=bottom align=middle>
Yes</P></TH>
<TH vAlign=bottom align=middle>
No</P></TH></TR>
<TR>
<TD vAlign=bottom colSpan=5>
Schematic Reference: <A
href="/servlets/CellHandler?CellId=69955&RefDoc=853460&evc=sm">Tra nsfer
Case Control Schematics</A> </P>
Connector End View Reference: <A
href="/servlets/CellHandler?CellId=69957&RefDoc=853460&evc=sm">Tra nsfer
Case Control Connector End Views</A> </P></TD></TR>
<TR>
<TD vAlign=center align=middle><A name=S01>
1</P></A></TD>
<TD vAlign=top align=left>
Did you perform the Diagnostic System Check - Transfer Case?</P></TD>
<TD vAlign=center align=middle>
--</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step2</P></TD>
<TD vAlign=bottom align=middle>
Go to <A
href="/servlets/CellHandler?CellId=69959&RefDoc=853460&evc=sm">Dia gnostic
System Check - Transfer Case</A> </P></TD></TR>
<TR>
<TD vAlign=center align=middle><A name=S02>
2</P></A></TD>
<TD vAlign=top align=left>
- <LI type=1>Set the parking brake.
<LI type=1>Raise the vehicle on a hoist.
<LI type=1>Disconnect the connector at the transfer case.
<LI type=1>Turn the ignition ON, with the engine OFF.
<LI type=1>Install a scan tool.
<LI type=1>While monitoring the encoder channels on the scan tool, short to
ground each of the encoder channel circuits on the module side of the harness
with a jumper wire. </LI>
Do more than one of the four encoder channels indicate OFF when each encoder
channel circuit is individually shorted to ground?</P></TD>
<TD vAlign=center align=middle>
--</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step5</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step3</P></TD></TR>
<TR>
<TD vAlign=center align=middle><A name=S03>
3</P></A></TD>
<TD vAlign=top align=left>
At the transfer case connector, using a DMM, test the encoder signal circuits
on the module side of the harness.</P>
Are the voltages within the specified range?</P></TD>
<TD vAlign=center align=middle>
4.3-4.7V</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step4</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step6</P></TD></TR>
<TR>
<TD vAlign=center align=middle><A name=S04>
4</P></A></TD>
<TD vAlign=top align=left>
With the ignition in the OFF position, test the encoder low reference circuit
for a short to ground, short to voltage, open, or high resistance. Refer to <A
href="/servlets/CellHandler?CellId=62194&RefDoc=853460&evc=sm">Cir cuit
Testing</A> and <A
href="/servlets/CellHandler?CellId=61965&RefDoc=853460&evc=sm">Wir ing
Repairs</A> in Wiring Systems.</P>
Did you find and correct the condition?</P></TD>
<TD vAlign=center align=middle>
--</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step11</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step7</P></TD></TR>
<TR>
<TD vAlign=center align=middle><A name=S05>
5 </P></A></TD>
<TD>
- <LI type=1>Disconnect C1 and C2 from the transfer case shift control module.
<LI type=1>Using a DMM, check for two or more encoder signal circuits being
shorted together. Refer to <A
href="/servlets/CellHandler?CellId=62194&RefDoc=853460&evc=sm">Cir cuit
Testing</A> and <A
href="/servlets/CellHandler?CellId=61965&RefDoc=853460&evc=sm">Wir ing
Repairs</A> in Wiring Systems. </LI>
Did you find and correct the condition?</P></TD>
<TD vAlign=center align=middle>
--</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step11</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step10</P></TD></TR>
<TR>
<TD vAlign=center align=middle><A name=S06>
6 </P></A></TD>
<TD vAlign=top align=left>
Test the suspect circuits for a short to ground, short to voltage, open, or
high resistance. Refer to <A
href="/servlets/CellHandler?CellId=62194&RefDoc=853460&evc=sm">Cir cuit
Testing</A> and <A
href="/servlets/CellHandler?CellId=61965&RefDoc=853460&evc=sm">Wir ing
Repairs</A> in Wiring Systems.</P>
Did you find and correct the condition?</P></TD>
<TD vAlign=center align=middle>
--</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step11</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step10</P></TD></TR>
<TR>
<TD vAlign=center align=middle><A name=S07>
7</P></A></TD>
<TD vAlign=top align=left>
- <LI type=1>Remove the encoder motor.
<LI type=1>Inspect the shift detent lever shaft for a binding condition. Refer
to <A
href="/servlets/CellHandler?CellId=69993&RefDoc=853460&evc=sm">Tra nsfer
Case Motor/Encoder Replacement</A> . </LI>
Did the shift detent lever shaft bind?</P></TD>
<TD vAlign=center align=middle>
--</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step8</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step9</P></TD></TR>
<TR>
<TD vAlign=center align=middle><A name=S08>
8</P></A></TD>
<TD vAlign=top align=left>
Remove the transfer case for disassembly and repair. Refer to <A
href="/servlets/CellHandler?CellId=72537&RefDoc=853460&evc=sm">Tra nsfer
Case Disassemble</A> .</P>
Did you complete the repair?</P></TD>
<TD vAlign=center align=middle>
--</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step11</P></TD>
<TD vAlign=center align=middle>
--</P></TD></TR>
<TR>
<TD vAlign=center align=middle><A name=S09>
9</P></A></TD>
<TD vAlign=top align=left>
Replace the encoder motor. Refer to <A
href="/servlets/CellHandler?CellId=69993&RefDoc=853460&evc=sm">Tra nsfer
Case Motor/Encoder Replacement</A> .</P>
Did you complete the repair?</P></TD>
<TD vAlign=center align=middle>
--</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step11</P></TD>
<TD vAlign=center align=middle>
--</P></TD></TR>
<TR>
<TD vAlign=center align=middle><A name=S10>
10</P></A></TD>
<TD vAlign=top align=left>
Replace the transfer case shift control module. Refer to <A
href="/servlets/CellHandler?CellId=69989&RefDoc=853460&evc=sm">Tra nsfer
Case Shift Control Module Replacement</A> .</P>
Did you complete the repair?</P></TD>
<TD vAlign=center align=middle>
--</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step11</P></TD>
<TD vAlign=center align=middle>
--</P></TD></TR>
<TR>
<TD vAlign=center align=middle><A name=S11>
11</P></A></TD>
<TD vAlign=top align=left>
- <LI type=1>Use the scan tool in order to clear the DTCs.
<LI type=1>Operate the vehicle within the Conditions for Running the DTC as
specified in the supporting text. </LI>
Does the DTC set?</P></TD>
<TD vAlign=center align=middle>
--</P></TD>
<TD vAlign=bottom align=middle>
Go to
Step1</P></TD>
<TD vAlign=bottom align=middle>
System OK</P></TD></TR></TBODY></TABLE>
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