Circuit Description
The Stoplamp Switch is normally closed. With the ignition in the RUN position and the brake pedal not depressed, the EBCM will have ignition voltage present at terminal 15 of the 24-way connector. When the brakes are applied, the voltage present at terminal 15 of the EBCM will be zero.
Conditions for Setting the DTC
| • | Vehicle above 56 km/h (35 mph) for 10 seconds, followed by vehicle at rest for 1 second. |
| • | Stoplamp never switching during the above condition |
Action Taken When the DTC Sets
| • | The ABS indicator lamp will not be illuminated |
| • | The ABS will not be disabled |
DTC C0281 is advisory code only. The DTC is stored in memory, but the ABS indicator lamp will not light, and ABS will not be disabled.
Conditions for Clearing the DTC
| • | Repair the conditions responsible for setting the DTC |
| • | Use the Scan Tool Clear DTCs function |
Diagnostic Aids
DTC C0281 can be set by a faulty Stoplamp Switch, mis-adjusted Stoplamp Switch or damage in CKT 848 or CKT 451. Also, a driver who rides the brake at power-up through 24 km/h (15 mph can set this DTC.
Thoroughly check any circuitry that is suspected of causing the intermittent complaint for the following conditions:
| • | Backed out terminals |
| • | Improper mating |
| • | Broken locks |
| • | Improperly formed or damaged terminals |
| • | Poor terminal to wiring connections |
| • | Physical damage to the wiring harness |
Test Description
The numbers below refer to the steps in the diagnostic table:
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This step checks the functionality of the Stop Lamp Switch circuit using the Scan Tool .
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This step checks the functionality of the Stop Lamp Switch circuit (including the Inverter Driving Module) using a J 39200 .
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This step checks the functionality of the Stop Lamp Switch circuit up to the Inverting Driving Module.
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This step checks for a short to ground in the Stop Lamp Switch circuit between the Inverting Driver Module and the EBCM.
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This step checks the resistance in the ground circuit to the Inverting Driver Module.
-
This step checks the ignition voltage at the Inverting Driver Module.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | |
Does the scan tool indicate that the Stop Lamp Switch is opening and closing? | -- | Go to Step 11 | Go to Step 3 | |
Is the voltage measured switching between the specified range? | 0-12 V | Go to Step 11 | Go to Step 4 | |
Disconnect the Inverting Driver Module harness connector. Is the voltage equal to or greater than the specified range? | 10 V | Go to Step 7 | Go to Step 5 | |
5 |
Is the voltage equal to or greater than the specified range? | 10 V | Go to Step 6 | Go to Step 12 |
6 | Using a J 39200 , measure the resistance between terminal A of the brake switch harness connector and terminal C of the Inverting Driver Module harness connector. Is the Stop Lamp Switch adjustment correct? | 0-2 ohms | Go to Diagnostic Aids | Go to Step 13 |
7 | Using a J 39200 , measure the resistance between terminal A of the Inverting Driver Module harness connector and terminal 15 of the 24-way EBCM harness connector. Is the resistance measured within the specified range? | 0-2 ohms | Go to Step 8 | Go to Step 15 |
Using a J 39200 , measure the resistance between terminal A of the Inverting Driver Module harness connector and ground. Is the resistance measured within the specified range? | OL | Go to Step 13 | Go to Diagnostic Aids | |
Using a J 39200 , measure the resistance between terminal D of the Inverting Driver Module harness connector and ground. Is the resistance measured within the specified range? | OL | Go to Step 10 | Go to Step 16 | |
Using a J 39200 , measure the voltage between terminal B of the Inverting Driver Module harness connector and ground. Is the voltage equal to or greater than the specified range? | 10 V | Go to Diagnostic Aids | Go to Step 17 | |
11 |
Does DTC C0281 set as a current code? | -- | Go to Step 19 | Go to Diagnostic Aids |
12 | Repair open in CKT 470. Refer to Wiring Repairs . Is the repair complete? | -- | -- | |
13 | Repair open in CKT 653. Refer to Wiring Repairs . Is the repair complete? | -- | -- | |
14 | Repair misadjusted or faulty brake switch. Is the repair complete? | -- | -- | |
15 | Repair open in CKT 848. Refer to Wiring Repairs . Is the repair complete? | -- | -- | |
16 | Repair open in CKT 652. Refer to Wiring Repairs . Is the repair complete? | -- | -- | |
17 | Repair open in CKT 654 or CKT 145. Refer to Wiring Repairs . Is the repair complete? | -- | -- | |
18 | Repair short to ground in CKT 848. Refer to Wiring Repairs . Is the repair complete? | -- | -- | |
19 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | -- |
