P0562-BATTERY VOLTAGE LOW
For a complete wiring diagram Refer to Section 8W
Theory of Operation
The Transmission Control Module (TCM) monitors ignition voltage. The DTC will set if the monitored battery voltage drops below 8.5 volts and a temporary limp in will be activated. If the voltage rises above 9.0 volts, normal operations is resumed and the TCM will record the DTC as a one trip fault. The DTC will only mature to a full DTC if the voltage is less than 8.5 volts with a engine speed greater than 2000 RPM for a least 60 seconds.
- When Monitored:
Continuously with the ignition on.
- Set Condition:
When monitored battery voltage drops below 8.5 volts.
| Possible Causes |
| ENGINE CHARGING SYSTEM DTCS |
| LOW BATTERY VOLTAGE |
| (F942) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT HIGH RESISTANCE |
| (Z904) GROUND CIRCUIT HIGH RESISTANCE |
| (F946) TRANSMISSION RELAY OUTPUT CIRCUIT HIGH RESISTANCE |
| TRANSMISSION RELAY |
| TRANSMISSION CONTROL MODULE |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)
Diagnostic Test
1. CHECK FOR ENGINE CHARGING SYSTEM DTCSWith the scan tool, read Engine DTCs.
Are there any Engine Charging System DTCs present?
Yes
- Refer to the 9 - ENGINE ELECTRICAL DIAGNOSTICS and perform the appropriate symptom.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)
No
- Go To 2
2. CHECK SYSTEM VOLTAGE
Start the engine.
With the scan tool, under transmission, check system voltage.
Is the transmission system voltage above 9.0 volts?
Yes
- Go To 7
No
- Go To 3
3. CHECK (F942) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT
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 (F942) Fused Ignition Switch Output (Run-Start) circuit in the Transmission Relay connector.
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?
Yes
- Go To 4
No
- Repair the (F942) Fused Ignition Switch Output (Run-Start) circuit for high resistance.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)
4. CHECK THE (F946) TRANSMISSION RELAY OUTPUT CIRCUIT
Turn the ignition off to the lock position.
Remove the Transmission Relay.
Connect a jumper wire between the (F942) Fused Ignition Switch Output (Run-Start) circuit and the (F946) Transmission Relay Output circuit in the Transmission Relay connector.
Start the engine.
With the scan tool, under transmission, check system voltage.
Is the transmission system voltage above 9.0 volts?
Yes
- Replace the Transmission Relay.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)
No
- Go To 5
5. CHECK THE (F946) TRANSMISSION RELAY OUTPUT CIRCUIT
Turn the ignition off to the lock position.
Disconnect the TCM C1 harness connector.
Ignition on, engine not running.
Using a 12-volt test light connected to ground, check the (F946) Transmission Relay Output circuit in the TCM C1 harness connector.
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?
Yes
- Go To 6
No
- Repair the (F946) Transmission Relay Output circuit for high resistance.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)
6. CHECK (Z904) GROUND CIRCUIT
Turn the ignition off to the lock position.
Using a 12-volt test light connected to 12-volts, check the (Z904) Ground circuit in the TCM C1 harness connector.
Does the test light illuminate brightly?
Yes
- Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the TCM per the Service Information. Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/TRANSMISSION CONTROL MODULE for the appropriate service procedures.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)
No
- Repair the (Z904) Ground circuit for high resistance.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)
7. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
Wiggle the wires while checking for shorted and open circuits.
Where there any problems found?
Yes
- Repair as necessary.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)
No
- Test Complete.