2014 Jeep Wrangler JK Factory Service Manual 28 - DTC-Based Diagnostics

B210A-SYSTEM VOLTAGE LOW

For a complete wiring diagram, refer to the Wiring Information.






Possible Causes

FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT OPEN
FUSED (B+) CIRCUIT OPEN
WIRELESS CONTROL MODULE (WCM)/SENTRY KEY REMOTE ENTRY MODULE (SKREEM)

1. DETERMINING IF DIAGNOSTIC TROUBLE CODE (DTC) IS CURRENT



NOTE: Diagnose any related Powertrain DTCs before continuing.
1. With a scan tool, read and record DTCs.
2. With the scan tool, clear DTCs.
3. Perform 5 ignition cycles, leaving the ignition switch on for a minimum of 90 seconds per cycle.
4. Using the scan tool, read DTCs.


Does the DTC reset?

Yes


No


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 DTCs.


Does the DTC reset?

Yes


No
DTC is not active at this time. Test complete.


3. FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT OPEN



NOTE: Check the related fuses to the Fused Ignition Switch Output (Run-Start) circuit. If the fuse is found to be open repair the circuit for a shorted condition.
1. Turn the ignition off.
2. Disconnect the WCM harness connector.
3. Turn the ignition on.
4. Using a 12 volt test light connected to ground, probe the Fused Ignition Switch Output (Run-Start) circuit in the WCM harness connector.


Does the test light illuminate brightly?

Yes


No


4. FUSED (B+) CIRCUIT OPEN

1. Turn the ignition off.
2. Using a 12 volt test light connected to ground, probe the Fused (B+) circuit in the WCM harness connector.


Does the test light illuminate brightly?

Yes


No


5. WCM



NOTE: Repeat the below procedure for both the Fused Ignition Switch Output (Run-Start) circuit and the Fused (B+) circuit.

NOTE: A dirty (partial) ground can cause abnormal conditions within a system. Ensure the module has a good ground before continuing.
1. Turn the ignition off.
2. Reconnect the WCM connector.
3. Back probe the Fused Ignition Switch Output (Run-Start) circuit and then the Fused (B+) circuit.
4. Start the engine.
5. Using the scan tool, view battery voltage under Data Display in the Engine category.
6. Compare the voltage on the scan tool to the voltage reading on the voltmeter.


Is the voltage on the scan tool equal to the voltmeter reading +/- .5 volt?

Yes


No