Transmission Control Module (TCM) - 8HP45

P0562-BATTERY/SYSTEM VOLTAGE LOW

For a complete wiring diagram Refer to the Wiring Information.

Theory of Operation

The purpose of the diagnostic is to monitor the system voltage level at the Transmission Control Module (TCM). If the TCM supply voltage drops below a calibrated level that is lower than the system voltage, then the high side switch is not activated and DTC P0562 is set.

- When Monitored:
When the ignition switch is turned to the run position and the high side switch is activated with the shifter in Park or Neutral.

Engine speed on the CAN BUS or the input speed signal is greater than a threshold with the shifter in Drive or Reverse.

Engine speed on the CAN BUS is greater than a threshold or engine speed signal on the CAN is invalid.

- Set Condition:
If the system voltage is less than a calibrated threshold then DTC P0562 is set.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. 8HP45 Pre-Diagnostic Troubleshooting Procedure

1. CHECK FOR ENGINE CHARGING SYSTEM DTCS
1. With the scan tool, read Engine DTCs.

Are any Engine Charging System DTCs present?

Yes

- Repair any Charging System DTCs before proceeding. After repairing the Charging System, perform the Transmission Verification test to verify the transmission and or controller was not damaged. 8HP45 Transmission Verification Test

No

- Go To 2

2. CHECK SYSTEM VOLTAGE
1. Start the engine.
2. With the scan tool, under transmission, check system voltage.

Is the transmission system voltage above 9.0 volts?

Yes

- Go To 3

No

- Go To 4

3. INTERMITTENT WIRING AND CONNECTORS
1. The conditions necessary to set this DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
3. Wiggle the wires while checking for shorted and open circuits.

Where any problems found?

Yes

- Repair as necessary.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Go To 4

4. CHECK THE BATT CIRCUIT
1. Ignition ON, Engine Not Running.
2. Using a 12-volt test light connected to ground, check the BATT circuit at the 16-way Transmission Control Module Assembly (TCMA) 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

- Replace and program the TCMA. Valve Body - Removal.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.

No

- Repair the BATT circuit for an open or high resistance.
- Perform the TRANSMISSION VERIFICATION TEST. Verification Tests.