Dodge-specific code — factory diagnostic data| DTC Data Sheet | |
| Code | C150A |
| System | TPMS / Wheels |
| Standard | Manufacturer Specific (Chrysler/Dodge) |
| Fault type | Circuit High |
| Official meaning | Left front tire pressure trigger module voltage high |
Definition source: Dodge factory description. Diagnostic guidance is based on factory-defined fault logic for this code.
C150A sets when the wireless control module reads the supply voltage at the left front trigger module higher than the design range. The trigger module is a small electronics package in the wheel well that wakes the in-tyre sensor and forwards its data to the wireless control module. An over-voltage report typically points at a wiring fault that has shorted the supply line to a higher-voltage source, or a failed trigger module reporting incorrect voltage.
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C150A Quick Answer
On a Dodge with trigger-module TPMS, C150A means the left front trigger module reports an over-voltage condition. Common causes are a short between the trigger module supply line and a battery feed, a failed trigger module, water intrusion at the wheel-well connector, or a damaged ground reference. The TPMS warning light will typically be illuminated and pressure data from the left front may not display.
The Diagnostic Procedure
You will need a scan tool that reads Dodge wireless control module codes, a DVOM, the appropriate wiring diagram for your specific model and year, and basic hand tools to access the left front wheel well.
- Confirm C150A and check for related TPMS codes at other wheels. Multiple-wheel faults usually point at the wireless control module or a power supply issue rather than a single trigger module.
- Check battery condition and charging output before any further work. Unstable supply can cause modules to misreport voltage values, especially during cranking.
- Raise the left front of the vehicle safely and remove the inner wheel well liner enough to access the trigger module. The left front module sits forward of the strut, often near the brake hose bracket.
- Inspect the trigger module connector for water staining, road salt deposits, green corrosion, and damaged terminals. Front-wheel locations see direct splash from the front tyre and accumulate contamination as quickly as the rears.
- With the key on, backprobe the supply pin at the trigger module connector. Verify voltage matches the model-specific spec. A reading well above system voltage confirms a wiring short to a higher-voltage source — a battery feed has crossed onto the supply circuit somewhere upstream.
- If voltage at the connector is correct, replace the trigger module — its internal voltage reference has drifted and is reporting an incorrect value.
- If voltage at the connector is high, disconnect the trigger module and re-measure at the harness. Trace the supply circuit back toward the body, looking for chafe damage at brackets, fender liner pass-throughs, and any prior accident repair area.
- Verify ground integrity at the trigger module. Voltage drop on the ground circuit under load should be minimal; high ground resistance can shift the module’s voltage reference and cause false high reports.
- Repair the wiring fault and/or replace the trigger module, clear the code, and drive the vehicle through a TPMS relearn cycle. The warning light should clear once the module recognises the trigger module’s pressure messages again.
Common Causes
- Short to higher voltage in the harness: Most common single cause. A chafed wire crosses to a battery feed at a body pass-through, often after a prior accident repair or aftermarket installation.
- Failed trigger module: The module’s internal voltage reference drifts after long-term moisture exposure and the module reports a false high reading. Replacement is the fix.
- Water intrusion at the connector: The wheel-well connector sees front-tyre spray and road salt. Corrosion at the pins changes the contact resistance and creates abnormal voltage readings.
- Poor or open ground: A high-resistance ground at the trigger module location shifts the module’s reference voltage. The module reads supply as elevated even when the actual supply is normal.
- Recent suspension or body repair with harness damage: Strut replacement, control arm replacement, or front body repair can pinch or chafe the trigger module harness.
- Wireless control module internal fault: Rare. Tends to present with multiple wheel-position codes rather than a single C150A.
Severity & Driving
C150A does not affect drivability. The engine, brakes, and steering work normally. You will lose tyre pressure monitoring at the left front wheel and the TPMS warning light will be on. The vehicle will not warn you if that tyre loses pressure — manually gauge-check tyre pressures every fuel fill until the fault is repaired. In jurisdictions where TPMS is required for inspection, the warning light may cause an inspection failure. Repair before any long trip.
FAQ
Why does the front need a trigger module when the rear does too?
Each wheel position has its own trigger module on this older LX-platform TPMS architecture. The trigger module wakes the dedicated in-tyre sensor with a low-frequency signal and relays the sensor’s response back to the central module. Without the trigger module, the in-tyre sensor stays asleep to conserve battery and the central module receives no data.
Will C150A cause my left front tyre to wear unevenly?
Not directly. The code is an electrical fault, not a mechanical one. The tyre wears based on alignment, inflation, and rotation history — those factors are unchanged. The risk is that you cannot detect underinflation at that wheel, which over time would cause inner-edge wear from running soft.
Can salt-belt corrosion alone cause C150A?
Yes. The wheel-well connector is exposed to road salt every winter and corrosion across the pins is a leading cause of trigger module faults on rust-belt LX cars. Cleaning and re-pinning the connector resolves many cases without parts replacement.
Should I replace all four trigger modules at once if one has failed?
Not as a routine practice. Each module has its own service life and replacing the whole set on one failure is unnecessary cost. If you find multiple modules with similar corrosion, the whole set may be near end of life — that is a judgment call based on the inspection findings, not a default approach.