Cadillac P1634: Ignition 1 Switch Circuit

Is your scanner showing Cadillac P1634?
No worries. We'll show you what it means and how to deal with it.

Presented by
Randy Worner

Cadillac P1634: Ignition 1 Switch Circuit

OVERVIEW
Severity
:
High
DIY Difficulty Level
:
Intermediate
Repair Cost
:
$130-$400
Can I Still Drive?
:
Yes

What Does The Cadillac P1634 Code Mean?

Conditions for Setting the DTC. Test Condition Engine running Failure Condition Voltage difference between Ignition 1, PCM C1-19, and Ignition 0, PCM C1-18, inputs greater than 2 volts for 5 seconds.

What Are The Potential Causes Of The Cadillac P1634 Code?

If this DTC is intermittent check terminal contact at the PCM and the condition of the CKT 639 splice for an intermittent open condition. A short to unswitched battery voltage on the Ignition 1 / Ignition Supplement circuit will set this DTC.

Recommended Parts

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

>>> Twippo 372Pcs Waterproof Wire Connectors Kit
>>> GM Genuine Parts Ignition Switch
>>> 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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