Circuit Description
The TCC normally closed brake switch supplies a B+ signal on CKT 420 to the PCM. The circuit is opened when the brakes are applied. The stop lamp/cruise control normally open brake switch supplies a B+ signal on CKT 820 to the PCM when the brake is applied. This is a type D DTC.
Conditions for Setting the DTC
| • | The switches disagree for 10 consecutive minutes. |
or
| • | The TCC and the cruise control brake switches are not toggling open and closed, during six brake applications on the same ignition cycle. |
Action Taken When the DTC Sets
The fourth gear operation in hot mode, and the cruise control operation
Conditions for Clearing the MIL/DTC
| • | A History DTC will clear after forty consecutive warm-up cycles during which the diagnostic does not fail (the coolant temperature has risen 5°C (40°F) from the start up coolant temperature and the engine coolant temperature exceeds 71°C (160°F) during that same ignition cycle. |
| • | Use of a Scan tool will clear the DTC codes. |
Diagnostic Aids
Refer to PCM Intermittent Diagnostic Trouble Codes or Performance. Check the driving habits of the customer and/or unusual traffic conditions (i.e. stop and go, expressway traffic).
Test Description
The number(s) below refer to the Step number(s) on the Diagnostic Table.
-
This test simulates brake switch closed or the brakes as being OFF.
-
This test checks the feed circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing the DTCs, use the Scan Tool Capture Info in order to record the Freeze Frame and the failure records for reference, as the data will be lost when the Clear Info function is used. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Does the Scan Tool display the Cruise Brake switch Closed and then Open when the brake is released? | -- | |||
Apply the brakes again. Does the Scan Tool display the Brake switch Open and then Closed when the brake is released? | -- | |||
4 |
Is the test light ON? | -- | ||
5 |
Does the Scan Tool display the Cruise Brake switch as Closed? | -- | ||
6 |
Is the test light ON? | -- | ||
7 |
Does the scan tool display the Cruise Brake switch as Closed? | -- | ||
8 | The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If any additional DTCs were stored, refer to the applicable DTC table(s) first. Are there any additional DTCs stored? | -- | Go to the Applicable DTC Table | Go to Diagnostic Aids |
9 | Check the normally open feed circuit (terminal B) for an open or a short to ground. Is the action complete? | -- | -- | |
10 | Check the normally open Cruise Brake switch signal circuit for an open or a short to ground. Was a repair performed? | -- | ||
11 | Check the normally open Cruise Brake switch signal circuit for a poor connection at the PCM. Was a repair performed? | -- | ||
12 | Check the normally closed feed circuit (terminal F) for an open or a short to ground. Is the action complete? | -- | -- | |
13 | Check the normally closed Brake switch signal circuit for an open or a short to ground. Was a repair performed? | -- | ||
14 | Check the normally closed Brake switch signal circuit for a poor connection at the PCM. Was a repair performed? | -- | ||
15 | Replace the stop lamp switch. Is the action complete? | -- | -- | |
16 | Replace the PCM. Important: If the PCM is malfunctioning, the new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | |
17 |
Does the Scan Tool indicate that this diagnostic Ran and Passed? | -- | ||
18 | Use the Scan Tool in order to select Capture Info, Review Info. Are there any DTCs displayed that have not been diagnosed? | -- | Go to the Applicable DTC Table | System OK |
