B162C – Left low beam control circuit high (Dodge)

B162C means the left low-beam headlight on your 2007 Dodge Charger may not work right, or it may act erratically. You usually notice a dark left side at night or a headlamp that stays on when it should not. According to Dodge factory diagnostic data, this code indicates “Left low beam control circuit high.” In plain terms, the body controller sees the left low-beam control wire staying too “high” when it expects a different state. That points to a wiring, connector, bulb, or control-module output issue, not an automatic “bad headlight” verdict.

B162C Quick Answer

B162C on a Dodge Charger points to the left low-beam control circuit reading high. Verify the circuit at the lamp and the controller before replacing the bulb or module.

What Does B162C Mean?

Official definition: “Left low beam control circuit high.” The module that runs exterior lighting detects an electrical condition on the left low-beam control circuit that stays higher than expected. In practice, that can shut the left low beam off, keep it on, or make it flicker, depending on how the Dodge lighting strategy reacts.

What the module is checking and why it matters: The body-side lighting controller does not just “command on.” It also monitors the control circuit for plausibility. A “circuit high” fault means the controller sees the control line stuck at a high electrical state when it expects it to be pulled low, loaded, or toggled. That matters because a stuck-high reading can come from an open load, a short to battery voltage, a poor ground that removes lamp load, or a damaged driver stage. The DTC identifies the suspected circuit, not the failed part.

Theory of Operation

On Dodge vehicles, the exterior lighting system uses a body controller to switch the headlamps based on the headlamp switch input and vehicle conditions. The controller routes power or ground to the left low-beam circuit through wiring and connectors to the left headlamp assembly. The lamp, its ground, and the harness provide a normal electrical load.

B162C sets when the controller commands or expects a certain circuit state and the feedback stays high. An open bulb filament, high resistance at the connector, or an open ground can remove the expected load. A short to battery voltage can also hold the circuit high. In some failures, the controller’s internal driver or connector pin tension causes the same “high” reading.

Symptoms

B162C usually shows up as a left low-beam lighting problem that you can see immediately.

• Left low beam out even though the right side works normally
• Left low beam stuck on with the switch off or in an unexpected mode
• Flicker or intermittent left low beam, often with bumps or steering movement
• Message/indicator for lamp outage or exterior lighting fault, if equipped
• High beams OK while the left low beam misbehaves, depending on lamp design
• Heat smell or visible melting at the left headlamp connector in severe resistance cases
• Code returns quickly after clearing, especially when commanding low beams on

Common Causes

• Control wire shorted to B+: Damaged insulation or pinched harness can feed battery voltage into the left low beam control circuit and force a “circuit high” interpretation.
• High resistance in the lamp ground path: Corrosion at the ground point can raise circuit voltage under load and make the module see an abnormally high control-side voltage.
• Connector water intrusion at the left headlamp: Moisture can bridge terminals and backfeed voltage onto the control circuit, especially with lighting loads active.
• Harness chafe near radiator support or fender area: Movement and vibration can rub through loom and contact power feeds, creating an intermittent high-voltage condition.
• Aftermarket HID/LED kit backfeed: Some ballasts or drivers feed voltage into the factory control wire and upset Dodge lamp monitoring logic.
• Incorrect bulb type or miswired bulb socket: A wrong bulb or swapped terminals can change current flow and create a false “high” reading at the control circuit.
• Internal fault in the lamp driver inside the body control module: A failed driver transistor can stick high or leak voltage onto the output, but confirm wiring first.
• Poor pin fit or terminal spread in the control circuit: Loose terminals can arc and create erratic voltage behavior that sets a high-circuit DTC.

Diagnosis Steps

You need a scan tool that reads Dodge body codes and shows live data for exterior lighting. Use a quality DVOM, a headlamp load (the installed bulb works), and back-probing tools. A test light can help, but do not use it on low-current logic circuits. Plan for voltage-drop tests with the headlamp commanded on.

1. Confirm DTC B162C and record all stored and pending body codes. Save freeze frame or failure records. Focus on battery voltage, ignition state, headlamp switch state, and any lamp command status at the moment the code set.
2. Check fuses and power distribution for the left low beam circuit first. Inspect the underhood and interior fuse blocks for heat damage. Do a quick visual check of the full circuit path to the left headlamp before meter work.
3. Verify module power and ground integrity under load. Command headlamps on and run a voltage-drop test on the module ground circuit. Keep the circuit operating and confirm less than 0.1V drop on the ground path.
4. Inspect the left headlamp connector and nearby harness. Look for green corrosion, overheated terminals, loose pin fit, or water trails. Pay attention to the radiator support area where harnesses often rub.
5. Check for non-OE lighting modifications. Identify HID/LED drivers, resistors, relays, or splices. Disconnect the aftermarket components and return the circuit to stock for testing.
6. Use the scan tool to command the left low beam on and off. Watch the related PID if available, such as “Left Low Beam Command” and any “Output Status” or “Fault State.” A hard fault often returns immediately when the driver commands the output.
7. Test the control circuit for a short to B+. With the lamp commanded off, back-probe the left low beam control circuit at the headlamp connector and at the module side. If you see battery voltage on the control line when it should rest low, isolate the harness by disconnecting the headlamp and then the module connector.
8. Load-test the ground and power at the headlamp while it operates. Measure voltage drop from the bulb ground to battery negative with the low beam on. Then measure voltage drop from battery positive to the bulb feed. High drop points to resistance that can skew the module’s circuit monitoring.
9. Check for backfeed through shared circuits. Turn on other lamps one at a time and monitor the left low beam control line for voltage rise. Backfeed often appears when park lamps, turn signals, or DRL functions run on nearby wiring.
10. If wiring, connectors, grounds, and modifications check out, evaluate the module driver. Confirm the control circuit does not short to B+ when disconnected from the module. If the line goes high only with the module connected, the driver likely leaks or sticks high.
11. After repairs, clear codes and run a verification cycle. Command lamps on and off several times. Use a scan tool snapshot during a road test if the fault was intermittent. Freeze frame shows conditions when the code set, while a snapshot captures live data when the concern happens.

Professional tip: Treat B162C as a “suspected area” code, not a part verdict. A circuit-high fault often comes from backfeed or a weak ground under load. Continuity checks can fool you because they use almost no current. Use voltage-drop testing with the lamp operating to catch resistance that only shows up under real load.

Possible Fixes

• Repair a short to B+ in the left low beam control wire: Restore insulation, reroute away from sharp edges, and secure the harness to prevent repeat chafing.
• Clean and tighten the left headlamp ground point: Remove corrosion, restore metal-to-metal contact, and confirm low voltage drop with the lamp on.
• Service connector terminals at the headlamp or module: Remove water intrusion, replace damaged terminals, and correct poor pin fit to stabilize control voltage.
• Remove or correct aftermarket lighting components: Eliminate backfeed sources and return wiring to a stock configuration before retesting.
• Replace the affected headlamp socket or pigtail: Use this only after you prove heat damage or terminal distortion causes voltage rise or backfeed.
• Replace the body control module only after circuit proof: Confirm the control line stays normal when disconnected from the module, then verify the driver forces the line high when connected.

Can I Still Drive With B162C?

You can usually drive a 2007 Dodge Charger with B162C, but you should treat it as a lighting safety issue. This code points to the left low beam control circuit reading “high,” which often leads to a left low beam that stays off, stays on, or acts erratically. Daytime driving may seem normal, yet you risk reduced visibility and poor oncoming traffic awareness at dusk or in rain. If the left low beam does not work, avoid night driving and bad weather. If the lamp stays on with the switch off, you can drain the battery while parked. Verify operation immediately before relying on the car for night travel.

How Serious Is This Code?

B162C ranges from inconvenient to safety-critical, depending on what the headlamp actually does. If the left low beam still turns on and off correctly, the issue may be intermittent wiring or a connector problem. That scenario often feels like a nuisance until it fails at night. If the left low beam stays off, you lose forward lighting and conspicuity on that side. That elevates risk on unlit roads and during storms. If the left low beam stays on, the car may strand you with a dead battery. This code does not usually affect engine drivability, but it can create legal and inspection problems. Treat it as a priority electrical fault.

Common Misdiagnoses

Technicians often replace the left low beam bulb first and stop there. A circuit-high DTC more often points to a control or wiring fault than a simple open filament. Another common mistake involves condemning the TIPM or headlamp driver without checking the harness under load. A control circuit can read “high” from a short to voltage, water intrusion, or a backfeed through an incorrect bulb type. Skipping connector pin-fit checks also wastes time. Loose terminals can mimic module failure. Avoid parts darts by confirming commanded state with a scan tool and then verifying control voltage, ground integrity, and voltage drop at the connector while the circuit is loaded.

Most Likely Fix

The most frequently confirmed repair paths for B162C involve correcting a wiring or connector fault at the left headlamp circuit, not immediate module replacement. Many cases trace to corrosion or pushed-out terminals at the headlamp connector, or damaged insulation that shorts the control circuit to battery voltage. Another common direction involves restoring proper ground integrity at the lamp assembly or body ground point, since poor grounds can cause abnormal feedback and false “high” readings. After repairs, confirm the fix by cycling the headlamp switch and high/low commands repeatedly and driving under the enable conditions that allow the body controller to re-run its lamp output diagnostics, which vary by Dodge platform.

Repair Costs

Repair cost depends on whether the confirmed root cause is a sensor, wiring, connector issue, or control module problem. Verify the fault electrically before replacing parts.

Last updated: March 31, 2026