On the Chrysler 300C with the 42RLE automatic transmission, P0935 means the PCM detected a Line Pressure Sensor voltage at or above 4.75 V — indicating the sensor circuit is stuck high, not that line pressure itself is actually elevated.
What P0935 means
The 42RLE transmission fitted to the 2005-2010 Chrysler 300C uses a Line Pressure Sensor (LPS) mounted on the valve body to report hydraulic line pressure to the Powertrain Control Module. The PCM continuously compares the sensor's feedback voltage (0.35-4.75 V normal range) against the commanded duty cycle of the Pressure Control Solenoid (PCS). P0935 sets when the LPS voltage stays at or above 4.75 V for at least 0.18 seconds with the ignition on and engine running -- the high-side threshold for the sensor's operating range. Because the circuit is shorted or the sensor has failed open, the PCM cannot confirm actual hydraulic pressure and defaults to maximum line pressure via the PCS (5% duty cycle = solenoid off = max pressure). This means shifts will be harsh but the transmission remains functional in limp mode. Note: the 5.7L HEMI 300C uses the NAG1 (W5A580) five-speed automatic, not the 42RLE; P0935 in that context refers to a different pressure sensor circuit within the NAG1 valve body.
Symptoms
- Illuminated check engine light with P0935 stored
- Harsh or firm gear shifts because the PCM defaults to maximum line pressure
- Possible transmission-related companion codes such as P0934 (line pressure circuit low) or solenoid performance codes
- Transmission may enter limited-function mode on some variants
- No improvement after warm-up -- the fault is electrical, not temperature-dependent
Common causes
- Failed Line Pressure Sensor on the 42RLE valve body -- the most common cause; the sensor is integral to the Variable Force Solenoid assembly on many variants
- Chafed or corroded wiring in the LPS signal circuit between the transmission harness connector and PCM connector C2
- Open circuit on the sensor ground (K900 circuit) preventing correct voltage reference
- PCM connector C2 corrosion or terminal push-back causing a false high-voltage reading
- Intermittent short to voltage on the LPS signal wire inside the transmission harness
Diagnostic approach
- Check the STARTS SINCE SET counter on a scan tool — If the counter is 2 or fewer, the fault is current and wiring diagnosis should begin immediately. A counter above 2 suggests an intermittent condition -- inspect harness connectors at the transmission and PCM for corrosion or pushed-out terminals before condemning the sensor.
- Test the LPS circuit with a Transmission Simulator (Miller tool #8333) — With the Starter Relay removed (prevents unintended starts in gear), connect the transmission simulator and set it to each of the three line pressure positions. Monitor the scan tool Line Pressure reading -- all readings should be within 14 kPa (2 psi) of the simulator's labelled value. If all three are within spec, the PCM and wiring are good and the Line Pressure Sensor itself must be replaced.
- Measure the (K900) Sensor Ground circuit resistance — With the PCM C2 connector disconnected and Miller tool #8815 installed, measure resistance from the LPS harness connector to the correct terminal at the PCM adapter. Any reading above 5.0 ohms indicates an open in the sensor ground -- repair that circuit before replacing the sensor.
Make & model notes
Chrysler: On the 300C with the 2.7L or 3.5L V6 and 42RLE, the Line Pressure Sensor is part of the Variable Force Solenoid assembly mounted inside the transmission pan. Replacing the sensor requires dropping the pan and unbolting the valve body assembly; many technicians replace the entire LPS/VFS assembly rather than the sensor alone to avoid recontamination issues.
Chrysler: The 42RLE Pre-Diagnostic Troubleshooting Procedure specified in the Chrysler factory manual must be completed before any DTC testing begins -- skipping it leads to misdiagnosis because adaptive shift data can mask true sensor failures during initial scan-tool tests.
FAQ
Can I drive a Chrysler 300C with P0935?
Short-term driving is possible because the 42RLE defaults to maximum line pressure when the sensor circuit fails high -- shifts become noticeably firmer but the transmission keeps working. However, sustained operation in this mode accelerates clutch pack wear, so repairs should not be deferred long.
Is P0935 on a Chrysler 300C always the Line Pressure Sensor?
Not always. The code indicates the circuit voltage is too high, which can result from a failed sensor, an open ground wire, a chafed signal wire touching a voltage source, or corrosion inside PCM connector C2. Always test the wiring before condemning the sensor.
Which Chrysler 300C models use the 42RLE transmission?
The 42RLE is a four-speed automatic used in 300C models with the 2.7L and 3.5L V6 engines for 2005-2010. The 5.7L HEMI models use the NAG1 (W5A580) five-speed automatic, which uses a different hydraulic pressure monitoring system. Confirm your transmission code before ordering parts.
Will P0935 on the Chrysler 300C clear itself?
No. P0935 is a continuous monitor -- the PCM checks the LPS voltage every time the engine runs. The code will re-set immediately on the next drive cycle unless the root cause is actually repaired.