GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1996 🢒 Camaro 🢒 DTC 🢒 DTC P1572 ASR/TCS Active CKT Low Voltage Too Long

Object Number: 21642 Size: SF
Engine Controls Components
Engine Data Sensors, TCS Active Signal, VSS Output
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The Traction Control Active circuit is a single wire from the PCM to the EBTCM. The PCM provides 12 Volts on this circuit and monitors the voltage. During a traction control event, the EBTCM grounds this circuit pulling the voltage low. The PCM interprets low signal voltage as traction control Active and high signal voltage as Inactive.

Conditions for Setting the DTC

The PCM determines that the Traction Control Active circuit has remained low for 6.4 seconds or more.

Action Taken When the DTC Sets
    • The PCM will illuminate the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
    • The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and/or Failure Records.
    • The injector will be disabled for the entire ignition cycle.

Conditions for Clearing the MIL/DTC
    • The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
    • A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.
    • A History DTC will clear after forty consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • PCM battery voltage is interrupted.
    • Using a Scan tool.

Diagnostic Aids

Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If the DTC cannot be duplicated, the information included in the Freeze Frame and/or Failure Records data can be useful in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also be used to determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that were noted. This will isolate when the DTC failed. For intermittents, refer to Symptoms .

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. The EBTCM also has diagnostics for this circuit which may have detected a problem and set a DTC within that system. Refer to ABS/TCS Diagnostic System Check. for additional information.

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2
  1. Install the scan tool.
  2. Turn the ignition ON, engine OFF.
  3. Monitor the Traction Control parameter on the scan tool.

Does the scan tool display Active?

--

Go to Step 4

Go to Step 3

3
  1. Turn the ignition ON, engine OFF, review Freeze Frame and/or Failure Records data for this DTC and note parameters.
  2. Turn the ignition OFF for 15 seconds.
  3. Start the engine and operate the vehicle within the conditions required for this diagnostic to run, and as close to the conditions recorded in Freeze Frame/Failure Records as possible. Special operating conditions that need to be met before the PCM will run this diagnostic where applicable, are listed in Conditions for Setting the DTC.
  4. Using the scan tool, select DTC, Specific, then enter the DTC number which was set.

Does the scan tool indicate that this diagnostic failed this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4
  1. Turn the ignition OFF.
  2. Disconnect the PCM connector C3.
  3. Turn the ignition ON.

Does the scan tool still display Active?

--

Go to Step 6

Go to Step 5

5

Check the Traction Control Active circuit for a short to ground, or an EBTCM problem. Refer to ABS/TCS Diagnostic System Check.

Is the action complete?

--

Go to Step 7

--

6

Important:: Replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Is the action complete?

--

Go to Step 7

--

7
  1. Using the scan tool, select DTC, Clear Info.
  2. Start the engine and idle at normal operating temperature.
  3. Select DTC, Specific, then enter the DTC number which was set.
  4. Operate the vehicle within the conditions for setting this DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test ran and passed?

--

Go to Step 8

Go to Step 2

8

Using the scan tool, select Capture Info, Review Info.

Are any DTCs displayed that have not been diagnosed?

--

Go to the applicable DTC table

System OK