Timing Reference High Resolution Signal A Malfunction
The PCM detected a malfunction with the high resolution timing reference signal A from the engine position sensor. This signal is critical for precise fuel injection and ignition timing, and a fault prevents the engine from running properly or at all.
What You Might Notice
- Engine will not start or cranks but does not fire
- Rough idle or severe misfiring
- Check Engine Light illuminated
- Loss of power or limp mode operation
- Vehicle may stall while driving
Most Common Causes
- 1
Faulty crankshaft position sensor
The CKP sensor that generates the high resolution signal has failed or is intermittently disconnecting. This is the most common cause of P0370.
- 2
Damaged reluctor ring or tone wheel
The toothed reluctor wheel on the crankshaft is cracked, broken, or has missing teeth, preventing proper signal generation to the sensor.
- 3
Wiring or connector problems
Broken, corroded, or loose wiring to the crankshaft position sensor, or a faulty connector, prevents signal transmission to the PCM.
- 4
Contaminated or degraded engine oil
Excessive metal particles or sludge in the oil can interfere with the sensor's ability to read the reluctor wheel pulses, especially on magnetic sensors.
How to Diagnose It
- 1
Check Faulty crankshaft position sensor — The CKP sensor that generates the high resolution signal has failed or is intermittently disconnecting. This is the most common cause of P0370.
- 2
Check Damaged reluctor ring or tone wheel — The toothed reluctor wheel on the crankshaft is cracked, broken, or has missing teeth, preventing proper signal generation to the sensor.
- 3
Check Wiring or connector problems — Broken, corroded, or loose wiring to the crankshaft position sensor, or a faulty connector, prevents signal transmission to the PCM.
- 4
Check Contaminated or degraded engine oil — Excessive metal particles or sludge in the oil can interfere with the sensor's ability to read the reluctor wheel pulses, especially on magnetic sensors.
How to Fix It
- 1
Replace crankshaft position sensor
Remove the faulty CKP sensor and install a new one. Verify correct installation and that the sensor air gap is set properly per manufacturer specifications.
- 2
Inspect and repair sensor wiring
Check the wiring harness and connectors for the crankshaft position sensor for damage, corrosion, or loose connections. Repair or replace damaged sections and ensure proper seating of connectors.
- 3
Replace reluctor ring or crankshaft
If the reluctor wheel is damaged, it must be replaced. This may require crankshaft replacement if the ring is integral to the crankshaft, or ring replacement if it is a separate component.
- 4
Perform engine oil change and flush
Change the engine oil and filter to remove contaminants that may be interfering with sensor operation. Check for internal engine damage if metal particles are found in the oil.
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