2007 Liberty KJ Factory Service Manual 21 - TRANSMISSION AND TRANSFER CASE

P0562-BATTERY VOLTAGE LOW





For a complete wiring diagram Refer to Section 8W.

Theory of Operation


Transmission damage may occur if there is insufficient supply voltage to properly control the solenoids. To prevent this possibility, the battery voltage is monitored and the system is placed in logical limp-in if the battery voltage drops below the limit.



Possible Causes
 
RELATED CHARGING SYSTEM DTC'S
 
(Z908) OR (Z977) GROUND CIRCUIT OPEN OR HIGH RESISTANCE
 
(A104) FUSED B+ CIRCUIT OPEN OR HIGH RESISTANCE
 
(T16) TRANSMISSION CONTROL RELAY OUTPUT TO TCM OPEN OR HIGH RESISTANCE
 
TRANSMISSION CONTROL RELAY
 
POWERTRAIN CONTROL MODULE
 


Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)



Diagnostic Test

1. CHECK FOR RELATED CHARGING SYSTEM DTC'S

With the scan tool, read the Engine DTC's.

Are there any Charging System related DTCs present?

Yes


No

2. CHECK IF THE DTC IS CURRENT

NOTE: Generator, battery, and charging system must be fully functional before performing this test.


With the scan tool, read DTCs.

Is the status for this DTC Active or the STARTS SINCE SET counter set at 0?

Yes


No

3. CHECK THE (Z908) AND (Z977) GROUND CIRCUITS FOR AN OPEN



Turn the ignition off to the lock position.
Disconnect the PCM C4 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 tool #8815 to perform diagnosis.


Using a 12-volt test light connected to 12-volts, check the (Z908) and (Z977) Ground circuits in the appropriate terminals of Miller tool #8815.

NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.



Does the test light illuminate brightly for all the Ground circuits?

Yes


No

4. CHECK THE (A104) FUSED B+ CIRCUIT FOR AN OPEN



Turn the ignition off to the lock position.
Remove the Transmission Control Relay.
Ignition on, engine not running.
Using a 12-volt test light connected to ground, check the (A104) Fused B+ circuit in the Transmission Control Relay connector.

Does the test light illuminate brightly?

Yes


No

5. CHECKING THE (T16) TRANSMISSION CONTROL RELAY OUTPUT CIRCUIT FOR AN OPEN



Turn the ignition off to the lock position.
Connect a jumper wire between (A104) Fused B+ circuit and the (T16) Transmission Control Relay Output circuit.
Ignition on, engine not running.
Using a 12-volt test light connected to ground, check all (T16) Transmission Control Relay Output circuits in the appropriate terminal of Miller tool #8815.

Does the test light illuminate brightly?

Yes


No

6. CHECK THE TRANSMISSION CONTROL RELAY

Turn the ignition off to the lock position.
Install a substitute Relay in place of the Transmission Control Relay.
Start the engine.
Using a voltmeter, measure the battery voltage.
With the scan tool, monitor the Transmission Switched Battery Voltage.
Compare the scan tool Transmission Switched Battery voltage to the actual battery voltage.

Is the scan tool voltage within 2.0 volts of the battery voltage?

Yes


No

7. 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 specific to this circuit.
Wiggle the wiring and connectors while checking for shorts and open circuits.
With the scan tool, check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set.

Were there any problems found?

Yes


No