Power Top Control Module (PTCM)
B210D-BATTERY VOLTAGE LOW
- When Monitored:
With the ignition on.
- Set Condition:
When battery voltage at the Power Top Control Module (PTCM) is less than 10 volts for over one minute.
Always perform the Power Top System Pre-Diagnostic procedure before proceeding. Power Top System Pre-Diagnostic Procedure.
1. DETERMINING IF DTC IS CURRENT
NOTE: Diagnose any related Powertrain DTC(s) before continuing.
1. With a scan tool, read and record PTCM DTCs.
2. With the scan tool, erase the DTCs.
3. Perform five ignition cycles, leaving the ignition switch on for a minimum of 90 seconds per cycle.
4. Using the scan tool, read the PTCM DTCs.
Does the scan tool display this DTC as Active?
Yes
- Go To 3
No
- Go To 2
2. INTERMITTENT CONDITION
NOTE: Check for any of the follow conditions:
- Poor wire to terminal connection
- Corroded terminals
- Backed out or loose terminals
- Broken wire internal to the insulation
- Dirty (partial) module ground
1. With the ignition on, wiggle the related wires.
2. Using a scan tool, read the DTCs.
Does the DTC reset?
Yes
- Repair the wiring as necessary.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
DTC is not active at this time. Test complete.
3. CHECK FOR MULTIPLE BATTERY VOLTAGE LOW DTCS
1. With a scan tool, read and record DTCs.
2. With the scan tool, clear DTCs.
3. Perform five ignition cycles, leaving the ignition switch on for a minimum of 90 seconds per cycle.
4. Using the scan tool, read DTCs.
Are multiple other modules reporting this DTC?
Yes
- Check the possible causes table above for conditions that can cause a system low voltage condition. Repair as necessary.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Go To 4
4. (A926) AND (A927) FUSED B(+) CIRCUITS OPEN
NOTE: Check the related fuses to the Fused B(+) circuits. If the fuses are found to be open, repair the circuits for a shorted condition.
1. Turn the ignition off.
2. Disconnect the PTCM C2 harness connector.
3. Turn the ignition on.
4. Using a 12 volt test light connected to ground, check the (A926) and (A927) Fused B(+) circuits in the PTCM C2 harness connector.
Does the test light illuminate brightly?
Yes
- Go To 5
No
- Repair the Fused B(+) circuits for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
5. (Z916) AND (Z908) GROUND CIRCUITS OPEN
1. Turn the ignition off.
2. Using a 12-volt test light connected to battery, check the (Z908) and (Z916) Ground circuits in the PTCM C2 harness connector.
Does the test light illuminate brightly in both Ground circuits?
Yes
- Go To 6
No
- Repair the (Z916) and (Z908) Ground circuits for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
6. CHECK SYSTEM VOLTAGE AT THE PTCM
1. Turn the ignition off.
2. Reconnect the PTCM C2 connector.
3. Start the engine.
4. Using the scan tool, view battery voltage under Data Display in the Engine category.
NOTE: The graphic shows the terminal end of the connector for reference only, back probe the wire end.
5. Using a voltmeter, back probe the (A926) and then the (A927) Fused B(+) circuits.
6. Compare the voltage on the scan tool to the voltage readings on the voltmeter.
NOTE: If charging system voltage readings are acceptable on both the scan tool and at the (A926 and A927) Fused (B+) circuits at the Power Top Control Module and no other modules are reporting this DTC then replacing the Power Top Control Module is the most likely course of action.
Is the voltage on the scan tool equal to the voltmeter readings (+/- 0.5 volt) back probed at the connector?
Yes
- Replace and program the Power Top Control Module in accordance with the the Service Information.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Repair the Fused (B+) circuits for high resistances.
- Perform the BODY VERIFICATION TEST. Body Verification Test.