02/08/2026 6:12 am
Topic starter
Automotive Q&A
P0327 appeared after intake work and the knock-sensor signal is flat
Review the evidence, add a focused answer, and distinguish confirmed measurements from assumptions.
Notifications
Clear all
Technical Questions
2
Posts
2
Users
0
Reactions
141
Views
0
A V6 engine developed P0327 immediately after an intake-manifold repair. The affected bank's knock signal is nearly flat compared with the other bank during the same controlled snap throttle. Connector seating at the accessible end looks normal and there was no code before the repair.
How can the buried sensor circuit be checked without assuming the new sensor failed?
1 Answer
0
03/08/2026 6:44 am
Start with the circuit diagram and compare resistance or bias from the control-module connector for both banks with the engine off. A side-to-side difference can identify an open or short without reopening the manifold immediately. Then inspect every harness routing and fastener location disturbed by the repair. If the circuit is piezoelectric, use the specified high-impedance test method and do not apply voltage to the sensor.
The timing of the fault makes installation damage more likely than simultaneous sensor failure. Open the intake only after the external and end-to-end checks point beneath it.
Topic starter
04/08/2026 7:31 am
Resistance from the ECM showed the affected circuit shorted to ground. Reopening the intake revealed the knock-sensor lead trapped under a manifold locating tab. The repaired harness matched the other bank, both signals responded together and P0327 stayed cleared.