engine is running but no rpms

73,000 MILES • 4.8L • V8 • FWD • AUTOMATIC
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BMET01
  • MEMBER
  • 1 POST
On way home from work, stopped at local store. Very rough start (like dead battery). Engine lurching forward or no power at all while driving and no RPM's showing on gauge.
Mar 31, 2014 at 6:53 AM
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SQM
  • ✓Experienced Mechanic
  • 6,383 POSTS
Hello,

It sounds like the vehicle might be in limp mode (low power mode).
Typically, the limp mode gets triggered when the vehicle diagnostic system detects a fault in the engine management system, it is there to protect the engine and transmission components from damaging.

https://www.2carpros.com/articles/reduced-power-limp-mode

Did the tachometer stop working the same time when this issue started?
It could be that the ECM is unable to detect the engine speed (RPM) and triggering the low power mode. The RPM will default to zero when there is an issue with the circuit.

Typically, with this type of issues the check engine light gets illuminated. Is your check engine light on? If so, having it scanned to get the codes can help with the diagnostics.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please let me know of any questions.
Thank you.
Oct 8, 2021 at 3:04 AM
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