Timing Reference High Resolution Signal B No Pulses
The PCM detects that the engine position sensor B (timing reference signal B) is not producing pulses. This sensor provides critical timing information for fuel injection and ignition, and loss of signal prevents proper engine synchronization.
What You Might Notice
- Check Engine Light illuminated
- Engine cranks but won't start or difficult starting
- Rough idle or misfires
- Loss of power or reduced fuel economy
- Possible limp mode activation
Most Common Causes
- 1
Faulty camshaft/crankshaft position sensor B
The sensor has failed internally or lost electrical continuity. This is the most common cause of no-pulse signal codes.
- 2
Damaged reluctor wheel
The tone ring or reluctor wheel that the sensor reads is cracked, broken, or misaligned, preventing signal generation.
- 3
Wiring or connector problems
Corroded connectors, damaged wiring harness, or loose connections between the sensor and PCM interrupt signal transmission.
- 4
Faulty PCM or module malfunction
The powertrain control module itself may have failed or cannot properly process the sensor signal.
How to Diagnose It
- 1
Check Faulty camshaft/crankshaft position sensor B — The sensor has failed internally or lost electrical continuity. This is the most common cause of no-pulse signal codes.
- 2
Check Damaged reluctor wheel — The tone ring or reluctor wheel that the sensor reads is cracked, broken, or misaligned, preventing signal generation.
- 3
Check Wiring or connector problems — Corroded connectors, damaged wiring harness, or loose connections between the sensor and PCM interrupt signal transmission.
- 4
Check Faulty PCM or module malfunction — The powertrain control module itself may have failed or cannot properly process the sensor signal.
How to Fix It
- 1
Test and replace position sensor B
Use a scope or multimeter to verify the sensor is producing pulses. If not generating signal, replace the camshaft or crankshaft position sensor as applicable for your vehicle.
- 2
Inspect wiring and connectors
Check the sensor connector for corrosion, loose pins, or damage. Test continuity in the wiring harness between sensor and PCM. Repair or replace damaged wiring.
- 3
Inspect reluctor wheel condition
Remove engine covers and visually inspect the tone ring or reluctor wheel for cracks, damage, or misalignment. Replace if damaged or realign if loose.
- 4
Test PCM function and reprogram
Verify PCM power and ground connections. If sensor and wiring are good, the PCM may need reprogramming or replacement by a dealer or specialist.
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