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For 1990-2009 cars only

DTC P1574 2.2L


Object Number: 891301  Size: MF

Circuit Description

The stop lamp switch is a normally open switch. When the stop lamp switch is closed and the brake pedal is pressed, then the engine control module (ECM) senses ignition voltage on the Stop Lamp Switch Signal circuit. If the ECM senses voltage on the TCC brake switch/cruise control release signal circuit when the torque converter clutch (TCC)/brake switch should be open, this DTC sets.

Conditions for Running the DTC

    • Vehicle has cycled from 0-60 km/h (0-37 mph) 3 times in 1 ignition cycle.
    • Continuous once the previous criteria have been met.

Conditions for Setting the DTC

The ECM does not detect a voltage state change on the stop lamp switch signal circuit after three stops. A high or low condition will set this code.

Action Taken When the DTC Sets

    • The ECM stores the DTC information into memory when the diagnostic runs and fails.
    • The malfunction indicator lamp (MIL) will not illuminate.
    • The ECM records the operating conditions at the time the diagnostic fails. The ECM 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: 

   • Verify that the stop lamp switch is adjusted properly. Refer to Stop Lamp Switch Adjustment in Lighting Systems.
   • If any of the stop lamps are not operating correctly refer to Stop Lamps Inoperative in Lighting Systems.
   • Test drive the vehicle if a switch or circuit condition cannot be located. An intermittent condition may be duplicated during a test drive.
   • For an intermittent, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step determines if the fault is present.

Step

Action

Yes

No

Connector End View Reference: Cruise Control Connector End Views

1

Did you perform the Diagnostic System Check - Cruise Control?

Go to Step 2

Go to Diagnostic System Check - Cruise Control

2

  1. Connect a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Monitor the stop lamp switch parameter in the engine control module (ECM) data list.

Does the Stop Lamp Switch parameter indicate Applied?

Go to Step 3

Go to Step 5

3

Verify that the stop lamp switch is adjusted correctly. Refer to Stop Lamp Switch Adjustment in Lighting Systems.

Did you find and correct the problem?

Go to Step 15

Go to Step 5

4

Inspect the stop lamp switch signal circuits for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the problem?

Go to Step 15

--

5

  1. Connect a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Depress the brake pedal while monitoring the stop lamp switch parameter in the ECM data list.

Does the stop lamp Switch parameter indicate Released?

Go to Step 6

Go to Diagnostic Aids

6

Verify that the stop lamp switch is adjusted correctly. Refer to Stop Lamp Switch Adjustment in Lighting Systems.

Did you find and correct the problem?

Go to Step 15

Go to Step 7

7

Do the stop lamps illuminate when the brake pedal is pressed?

Go to Step 11

Go to Step 8

8

Inspect for poor connections at the harness connector of the stop lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 9

9

Inspect the Ignition voltage supply to the stop lamp switch circuits for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the problem?

Go to Step 15

Go to Step 10

10

Inspect the stop lamp switch Signal circuits for short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the problem?

Go to Step 15

Go to Step 12

11

Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 13

12

Replace the TCC/brake switch. Refer to Stop Lamp Switch Replacement in Lighting Systems.

Did you complete the repair?

Go to Step 15

--

13

Inspect the stop lamp switch Signal circuit for an open circuit in the branch between the integrated body control module (IBCM) and the ECM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 14

14

Important: The replacement ECM must be programmed.

Replace the ECM. Refer to Engine Control Module Replacement in Engine Controls.

Is the action complete?

Go to Step 15

--

15

  1. Use a 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