GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2001 🢒 Corvette 🢒 Suspension 🢒 Real Time Damping (RTD) 🢒 DTC P1652

Circuit Description

The PCM controls the Powertrain Induced Chassis Pitch by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the controlled component. The driver has a fault line which is monitored by the PCM. When the PCM commands a component ON, the voltage of the control circuit should be low, near 0 volts. When the PCM commands the control circuit to a component OFF, the voltage potential should be a high 5 volts (+/- 0.5 volts). If the fault detection circuit senses a voltage other than what the system expects, the fault line status changes causing the DTC to set.

The PCM receives an 5 volt (+/- 0.5 volt) reference signal from the electronic suspension control (ESC) module on the Powertrain Induced Chassis Pitch circuit. The PCM grounds this circuit when the vehicle accelerates rapidly or brakes hard. When the chassis pitch input circuit goes low to about 0 volts, the ESC module commands all four shock absorber solenoids to a firm position. The PCM calculates the chassis pitch information based on the engine torque and the vehicle braking force.

Conditions for Running the DTC
    • Engine speed greater than 400 RPM.
    • The system voltage is greater than 6 volts but less than 18 volts.

Conditions for Setting the DTC
    • The PCM detects that the commanded state of the driver and the actual state of the control circuit do not match.
    • The condition must exist for a minimum of 5.0 seconds.

Action Taken When the DTC Sets
    • The PCM stores the DTC information into memory when the diagnostic runs and fails.
    • The malfunction indicator lamp (MIL) will not illuminate.
    • The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

Conditions for Clearing the DTC
    • A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
    • A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
    • Use a scan tool in order to clear the DTC.

Diagnostic Aids

Important: 

   • Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the module. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.
   • For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616 . Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.

    • Ensure that the vehicle is equipped with electronic suspension control (ESC). This DTC sets when the body control module (BCM) is programmed if the regular production option (RPO) for the ESC is selected as active and the vehicle is not equipped with ESC.
    •  For an intermittent condition refer to Symptoms - Engine Controls .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step determines if the Powertrain Induced Chassis Pitch control circuit is shorted to ground.

    2.

  2. This step determines if the Powertrain Induced Chassis Pitch control circuit is open or, the PCM is unable to control the Powertrain Induced Chassis Pitch control circuit.

Step

Action

Yes

No

Schematic Reference: Suspension Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls in Engine Controls - 5.7L

2

  1. Turn OFF the ignition.
  2. Install a scan tool.
  3. Disconnect the Electronic Suspension Control (ESC) Module connector C2. Refer to Electronic Suspension Control Module Replacement in Real-Time Damping (RTD).
  4. Pull the terminal in the C5 position out of the C2 connector.
  5. Connect the C2 connector back into the ESC module.
  6. Turn ON the ignition leaving the engine OFF.
  7. Probe the Powertrain Induced Chassis Pitch Control circuit at the ESC terminal end using the test lamp J 35616-200 connected to B+.

Does the test lamp illuminate?

Go to Step 4

Go to Step 3

3

Command the Chassis Pitch Signal ON using the scan tool.

Does the test lamp illuminate?

Go to Diagnostic System Check - Real Time Damping

Go to Step 5

4
  1. Test the Chassis Pitch Control circuit for a short to ground. Refer to Testing for Continuity in Wiring Systems.
  2. If you find a grounded circuit , repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 7

5
  1. Test the Chassis Pitch Control circuit for an open. Refer to Testing for Continuity in Wiring Systems.
  2. If you find an open circuit, repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 6

6
  1. Inspect for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. If you find a poor connection, repair the terminal as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 7

7

Important: Program the replacement PCM. Refer to Powertrain Control Module Programming in Engine Controls - 5.7L.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 5.7L..

Did you complete the replacement?

Go to Step 8

--

8
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK