What Does P0348 Mean?
The ECM has detected that the camshaft position sensor A signal on Bank 2 is reading above the expected maximum voltage, typically exceeding 4.8V continuously. This high input indicates the signal wire is being pulled to battery voltage or the sensor's reference voltage without the normal signal modulation from the reluctor wheel. The engine will likely run poorly on the Bank 2 cylinders and may default to sequential injection disable mode.
Common Causes
35%
Short to battery voltage in the CMP sensor A signal wire on Bank 2, commonly where harness contacts alternator output wire or B+ connections
30%
Failed CMP sensor A (Bank 2) with internal failure causing output to latch high
20%
Open ground circuit to the CMP sensor preventing proper signal return path, biasing output high through the reference voltage
15%
ECM internal pull-up circuit fault or signal input driver failure
Diagnostic Steps
1
Disconnect the Bank 2 CMP sensor A and measure voltage on the signal wire from the ECM side with KOEO. If the signal reads above 4.5V with sensor disconnected, suspect a short to power in the harness or ECM fault.
2
With the sensor disconnected, check for continuity between the CMP signal wire and battery positive terminal. Any measurable continuity confirms a short to voltage in the harness.
3
Verify the CMP sensor ground circuit has less than 0.5 ohms resistance to ECM sensor ground. An open ground will cause the signal to float high through the reference voltage pull-up.
4
Inspect the Bank 2 CMP sensor harness routing near the alternator, starter, and ignition coil power feeds where chafing against high-voltage wires is most likely.
5
Install a known-good CMP sensor and verify proper square wave signal output (0-5V) on an oscilloscope at idle. Confirm the signal amplitude and frequency match Bank 1 for comparison.
Estimated Repair Cost
$75 - $375
Parts + labor, varies by vehicle and location
The ECM has detected that the camshaft position sensor A signal on Bank 2 is reading above the expected maximum voltage, typically exceeding 4.8V continuously. This high input indicates the signal wire is being pulled to battery voltage or the sensor's reference voltage without the normal signal mod...
The most common cause of P0348 (Camshaft Position Sensor A Circuit High Input (Bank 2)) is: Short to battery voltage in the CMP sensor A signal wire on Bank 2, commonly where harness contacts alternator output wire or B+ connections
Typical repair costs for P0348 range from $75 to $375, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A continuously high CMP signal eliminates the ECM's ability to determine camshaft position on Bank 2, causing degraded engine performance, rough running, and possible stalling during deceleration.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0348 to identify the root cause.
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Quick Info
Category
Powertrain
System
Engine Timing / Variable Valve Timing
Difficulty
Type
Generic (SAE)
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