DaimlerChrysler Jeep Grand Cherokee 2002 Service Manual page 165

P0703-BRAKE SWITCH SIGNAL CIRCUITS PLAUSIBILITY WITH RE -
DUNDANT CONTACT —
TEST
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?
Yes → Go To 12
→ Repair the Brake Lamp Switch Fused B+ circuit for an open.
No
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?
Yes → Adjust or replace the Brake Lamp Switch in accordance with the
→ Go To 13
No
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?
Yes → Repair the Primary Brake Switch Signal circuit for a short to
→ Go To 14
No
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?
Yes → Replace and program the Engine Control Module in accordance
→ Repair the Primary Brake Switch Signal circuit for an open.
No
Continued
ACTION
Perform ROAD TEST VERIFICATION - VER-2.
Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
Perform ROAD TEST VERIFICATION - VER-2.
DRIVEABILITY - DIESEL
157
APPLICABILITY
All
All
All
All