Cadillac P1643: Engine Speed (RPM) Output Circuit Malfunction

Is your scanner showing Cadillac P1643?
No worries. We'll show you what it means and how to deal with it.

Presented by
Randy Worner

Cadillac P1643: Engine Speed (RPM) Output Circuit Malfunction

OVERVIEW
Severity
:
High
DIY Difficulty Level
:
Intermediate
Repair Cost
:
$100-$350
Can I Still Drive?
:
No

What Does The Cadillac P1643 Code Mean?

Engine started, engine speed over 600 rpm, and the PCM detected the commanded state of Engine Speed signal driver and Actual state of the driver did not match for 25.5 seconds.

What Are The Potential Causes Of The Cadillac P1643 Code?

Below are some potential causes of this DTC:

  • Engine speed signal circuit is open, shorted to ground or to B+
  • Instrument Cluster is damaged or has failed
  • PCM has failed

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

>>> WORKPRO 582-piece Crimp Terminals, Wire Connectors, Heat Shrink Tube, Electrical Repair Kit
>>> BPR Instrument Cluster Compatible with 2003-2004 Cadillac Escalade
>>> GM Genuine Parts 12633238 Engine Control Module

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Reference Sources

GM, 2013, Service Bullettin – Prior To Any Circuit Testing.

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