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Home >> Chevrolet >> 2012 >> Camaro LS, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 165 (Horn System) >> Diagnostic Information and Procedures >> Horns Inoperative >> Test Example - Discrete (Switch) Signal Circuit Pulled High Or Low In The Control Module, Using a DMM

Test Example - Discrete (Switch) Signal Circuit Pulled High Or Low In The Control Module, Using a DMM

WARNING: This page is about a different car, the 2011 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: The signal circuit template testing uses a scan tool parameter to verify the signal circuit functions. When there is no scan tool parameter supported or an active parameter when there's an open circuit condition, use the following test in place of using the scan tool. This test does not verify the circuit between the control modules internal pull up resister and the micro-processor chip.
Signal circuit tests when there is no scan tool support.

Pulled High In The Control Module

  1. Ignition ON.
  2. Test for 4.8-5.2 V between the signal circuit terminal [X] and ground.
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the harness connector at the [CC] [XX] control module.
    2. Test for infinite resistance between the signal circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • If infinite resistance
  3. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the [CC] [control module].
    • If greater than for 5.2 V 
    1. Ignition OFF, disconnect the harness connector at the [CC] [XX] control module, ignition ON.
    2. Test for less than 1 V between the signal circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, replace the [CC] [control module].
    • If within 4.8-5.2 V 

Pulled Low In The Control Module

  1. Ignition OFF.
  2. Test for XX-YY Ω between the signal circuit terminal [X] and ground.
    • If less than XX Ω 
    1. Disconnect the harness connector at the [CC] [XX] control module.
    2. Test for infinite resistance between the signal circuit and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • If infinite resistance, replace the [CC] [control module].
    • If greater than for YY Ω 
    1. Disconnect the harness connector at the [CC] [XX] control module, ignition ON.
    2. Test for less than 1 V between the signal circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V
  3. Ignition OFF.
  4. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the [CC] [control module].
    • If within XX-YY Ω 
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