When Monitored:
With the ignition on. Battery voltage greater than 10 volts.
Set Condition:
An open condition of the Transmission Control Output circuit is detected by the Totally Integrated Power Mod-
ule (TIPM).
Possible Causes
(T16) TRANSMISSION CONTROL OUTPUT CIRCUIT OPEN
TOTALLY INTEGRATED POWER MODULE (TIPM)
Diagnostic Test
1.CHECK IF THE DTC IS ACTIVE
Ignition on, engine not running.
With the scan tool, select View DTCs.
Is the status Active for this DTC?
Ye s>>
Go to 2
No>>
Go to 4
2.CHECK THE (T16) TRANSMISSION CONTROL OUTPUT CIRCUIT FOR AN OPEN
Turn the ignition off to the lock position.
Disconnect the PCM C4 harness connector and install Miller tool #8815.
Disconnect the Transmission Solenoid harness connector.
Disconnect the Line Pressure Sensor/Variable Force Solenoid harness
connector (if equipped).
CAUTION: 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 tool #8815 to per-
form diagnosis.
Ignition on, engine not running.
Using the scan tool under the TIPM Actuators, actuate the Transmis-
sion.
Using a 12-volt test light connected to ground, check the (T16) Trans-
mission Control Output circuits.
NOTE: The test light must illuminate brightly. Compare the bright-
ness to that of a direct connection to the battery.
Does the test light illuminate brightly?
Ye s>>
Go To 3
No>>
Repair the (T16) Transmission Control Output circuit for an
open.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
When Monitored:
With the ignition on. Battery voltage greater than 10 volts.
Set Condition:
An overcurrent condition is detected in the TCM Power Control circuit. OneTrip Fault. Three good trips to turn
off the MIL.
Possible Causes
LINE PRESSURE SENSOR VARIABLE FORCE SOLENOID
SOLENOID/PRESSURE SWITCH ASSEMBLY
POWERTRAIN CONTROL MODULE (PCM)
TOTALLY INTEGRATED POWER MODULE (TIPM)
Diagnostic Test
1.CHECK IF THE DTC IS ACTIVE
Ignition on, engine not running.
With a scan tool, read TIPM DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Go To 5
2.CHECK THE (T16) TRANSMISSION CONTROL OUTPUT
Turn the ignition off.
Disconnect the TIPM C10 harness connector.
Connect the positive probe of an ammeter to battery positive and con-
nect the negative probe to the (T16) Transmission Control Output circuit
in the TIPM C10 harness connector.
Read the amperage on the ammeter.
Does the amperage read below 2.0 amps?
Ye s>>
Go To 4
No>>
Go To 3
3.CHECK THE PCM
Disconnect the amp meter from the TIPM C10 harness connector and
battery positive.
Disconnect the PCM C4 harness connector.
Reconnect the positive probe of an ammeter to battery positive and
connect the negative probe to the (T16) Transmission Control Output
circuit in the TIPM C10 harness connector.
Read the amperage on the ammeter.
Does the amperage read below 2.0 amps?
Ye s>>
Using the schematics as a guide, check the Powertrain
Control Module (PCM) terminals for corrosion, damage, or
terminal push out. Pay particular attention to all power and
ground circuits. If no problems are found, replace the PCM
per the Service Information.With the scan tool, perform
QUICK LEARN
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 4
4.CHECK THE TRANSMISSION SOLENOIDS
Disconnect the amp meter from theTIPM C10 harness connector.
Disconnect the PCM C4 harness connector and install Miller tool #8815.
Connect the positive probe of an ammeter to battery positive and con-
nect the negative probe to the (T16) Transmission Control Output circuit
in the TIPM C10 harness connector.
While monitoring the amperage reading of the ammeter and using a
jumper wire, jump each solenoid control circuit to ground one at a time
in the appropriate terminals of Miller tool #8815.
NOTE: The amperage draw should be approximately .02 milliam-
pere on each solenoid circuit with the PCM C4 harness connector
disconnected.
Does the amperage read between .05 and .015 milliampere ±
.005 milliampere on each solenoid tested?
Ye s>>
Replace the Totally Integrated Control Module per the Ser-
vice Information.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Depending on the identified circuit in the test, replace either
Transmission Solenoid/Pressure Switch Assembly or the
Line Pressure Solenoid (if equipped) per the Service Infor-
mation.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
P1684-BATTERY WAS DISCONNECTED
For a complete wiring diagramRefer to Section 8W.
When Monitored:
After a reset (ignition key turned to the RUN position).
Set Condition:
The checksum of the battery backed RAM does not match the stored checksum. Set Time: Less than 7 msec.
Possible Causes
BATTERY WAS DISCONNECTED
PCM WAS REPLACED OR DISCONNECTED
QUICK LEARN WAS PERFORMED
(A919) FUSED B+ CIRCUIT TO PCM OPEN
(Z908 and Z977) GROUND CIRCUIT OPEN
Always perform the 42RLE Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
Theory of Operation
Note: This is not a fault code. It exists to provide reference information only. A battery backed RAM is used to
maintain some learned values. When the battery is disconnected, this memory is lost. When the battery is recon-
nected, the loss of learned values will be detected by the controller. The code will be set and the learned values will
be initialized to known constants and the learning process will continue.Setting the code has no effect except for
re-initialization of learned values.
Diagnostic Test
1.BATTERY WAS DISCONNECTED
Has the battery been disconnected, lost it’s charge, or been replaced recently?
Ye s>>
Disconnecting or replacing the battery will set this DTC. Erase the DTC.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 2
2.WAS QUICK LEARN PERFORMED
Has a Quick Learn procedure been performed?
Ye s>>
Performing Quick Learn will set this DTC. Erase the DTC.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 3
3.PCM REPLACED OR DISCONNECTED
Has the PCM been replaced or disconnected?
Ye s>>
Replacing or disconnecting the PCM will set this DTC. Erase the DTC.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 4
4.(A919) FUSED B(+) CIRCUIT
Turn the ignition off to the lock position.
Disconnect the PCM C1 harness connector.
NOTE: Check connectors - Clean/repair as necessary.
CAUTION: 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.
Using a 12-volt test light connected to ground, check the (A919) Fused
B(+) circuit.
NOTE: The test light must illuminate brightly. Compare the bright-
ness to that of a direct connection to the battery.
Does the test light illuminate brightly?
Ye s>>
Go To 5
No>>
Repair the Fused B+ circuit for an open. If the fuse is open
make sure to check for a short to ground.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
5.(Z908) AND (Z977) GROUND CIRCUITS
Turn the ignition off to the lock position.
Disconnect the PCM C4 harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Using a 12-volt test light connected to 12-volts, check the (Z908) and
(Z977) Ground circuits in the appropriate terminal of Miller tool #8815.
NOTE: The test light must illuminate brightly. Compare the bright-
ness to that of a direct connection to the battery.
Does the test light illuminate brightly for all of the ground cir-
cuits?
Ye s>>
Go To 6
No>>
Repair the Ground circuits for an open.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
6.INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set the DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specifictothiscircuit.
Wiggle the wires while checking for shorted and open circuits.
With the scan tool, check the DTC EVENT DATA to help identify the conditionsin which the DTC was set.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
3.PCM AND WIRING
Turn the ignition off to the lock position.
Remove the Ignition Switch Feed fuse from the TIPM.
CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being
startedingear.
WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in
personal injury or death.
Install the Transmission Simulator,Miller tool #8333 and the ElectronicTransmission Adapter kit.
Ignition on, engine not running.
With the Transmission Simulator, turn the Pressure Switch selector switchtoL/R.
With the scan tool, monitor the L/R Pressure Switch State while pressing the Pressure Switch Test button.
Did the Pressure Switch state change from open to closed when the test button was pressed?
Ye s>>
Repair internal transmission as necessary per the Service Information. Inspect the Solenoid Switch
Valve per the Service Information and repair or replace as necessary. If noproblems are found, replace
the Transmission Solenoid/Pressure Switch Assembly.
Perform 42RLE TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)
No>>
Go To 4
4.(T16) TRANSMISSION CONTROL OUTPUT CIRCUIT OPEN
Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid/Pressure Switch Assembly har-
ness connector.
Disconnect the PCM C4 harness connector.
With the scan tool under TIPM, actuate the Transmission.
CAUTION: 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 tool #8815 to per-
form diagnosis.
Using a 12-volt test light connected to ground, check all (T16) Trans-
mission Control Relay Output circuits in the appropriate terminals of
Miller tool #8815.
NOTE: The test light must illuminate brightly. Compare the bright-
ness to that of a direct connection to the battery.
Does the test light illuminate brightly on all (T16) Transmission
Control Output circuits?
Ye s>>
Go To 5
No>>
Repair the (T16) Transmission Control Relay Output circuit
for an open.
Perform 42RLE TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - 42RLE - STANDARD PROCEDURE)
When Monitored:
Every 7 msec with:
1) Engine speed greater than 500 RPM.
2) Battery voltage between 10 and 16 volts.
Set Condition:
CAN C BUS messages are not received for 10 seconds.
Theory of Operation
The NGC controller communicates over the CAN C BUS. The transmission controller continuously monitors BUS
activity. The CAN C BUS is also used to communicate transmission MIL statusto the Engine Controller. If the
Engine Controller is unable to communicate with the Transmission Controller, a DTC will set and the Engine Con-
troller will illuminate the MIL.
Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING for diagnostic
procedures and for further possible causes.