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Joel, Auto technician
Category: Chevy
Satisfied Customers: 1603
Experience:  GM, ASE Certified Technician. Chevy, Buick, Pontiac, Olds. Over 18 Years experience and growing.
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2001 chevy: code that came up on scanner..1500 5.3l can you tell me

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i have a code that came up on scanner of a 2001 chevy 1500 5.3l can you tell me what this code is and how to fix it.

Hello and welcome.

If you give me the code number, i will do my best to help solve your problem.


Customer: replied 7 years ago.
p1638c is the code and also i have another code if you can help me out too. po332b and i think this is a knock sensor and how would i replace this sensor. also if you can help me out on this one. i will be driving down the road and the parking break light and abs light will come on and stay on until i shut the truck off and it may not come back on for days. what is the problem here.

The ABS light will also cause the red brake light.

Common causes are any of the whel speed sensors or harness going to a speed sensor.


P1638 is alternator circuit problem. Either a bad alternator, computer, or wiring to the alternator. Would need a volt meter to test if the alt is charging. If ok, would need a scanner that shows live data to test the circuits.


P0332 is for knock sensor. Sensor(s) located under the intake manifold.

We have had problem with water getting into the valley where the sensors are and causing corrosion. If that look OK, then it is normally just a sensor problem.


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