DaimlerChrysler Jeep Grand Cherokee 2002, Service Manual

Page: 165 / 284

TEST ACTION APPLICABILITY
11 Disconnect the Brake Lamp Switch harness connector.
Using a 12-volt test light connected to ground, check the Fused B+ circuit.
Does the test light illuminate brightly? All
Yes
→
Go To 12
No
→
Repair the Brake Lamp Switch Fused B+ circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
12 Disconnect the Brake Lamp Switch harness connector.
Turn the ignition on.
While monitoring the PRIM BRAKE SWITCH status with the DRB, connect a
jumper wire between the Primary Brake Switch Signal circuit and the Fused B(+)
circuit.
Does the DRB display change from RELEASED to PRESSED? All
Yes
→
Adjust or replace the Brake Lamp Switch in accordance with the
Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No
→
Go To 13
13 Turn the ignition off.
Disconnect the Brake Lamp Switch harness connector.
Disconnect the ECM harness connectors.
Remove the ASD Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay connector.
Turn the ignition on.
Measure the voltage between the Primary Brake Switch Signal circuit and ground.
Is the voltage above 1.0 volt? All
Yes
→
Repair the Primary Brake Switch Signal circuit for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No
→
Go To 14
14 Turn the ignition off.
Disconnect the Brake Lamp Switch harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the Primary Brake Switch Signal circuit.
Is the resistance below 5.0 ohms? All
Yes
→
Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No
→
Repair the Primary Brake Switch Signal circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
157
DRIVEABILITY - DIESEL
P0703-BRAKE SWITCH SIGNAL CIRCUITS PLAUSIBILITY WITH RE-
DUNDANT CONTACT —
Continued
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