Pinpoint Test K: The Brake Warning Indicator Is Never/Always On - Ford Mustang 2005 Workshop Manual

2005 Mustang Workshop Manual
instrument cluster
PINPOINT TEST J: THE CHECK FUEL CAP WARNING INDICATOR IS NEVER/ALWAYS ON
J1 RETRIEVE THE RECORDED POWERTRAIN CONTROL MODULE (PCM) DTCs FROM BOTH
CONTINUOUS AND ON-DEMAND SELF-TESTS
Check for recorded PCM DTCs from the continuous and on-demand self-tests.
Are any PCM DTCs recorded?
J2 CARRY OUT THE INSTRUMENT CLUSTER WARNING LAMPS AND CHIME ACTIVE
COMMAND USING THE DIAGNOSTIC TOOL
Ignition ON.
Enter the following diagnostic mode on the scan tool: Instrument Cluster Active Command.
Select the instrument cluster warning lamps and chime active command. Trigger the all lamps
active command on and off. Observe the check fuel cap indicator.
Does the check fuel cap indicator illuminate when triggered on and turn off when
triggered off?
J3 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION
Disconnect the instrument cluster connector.
Check for:
corrosion
pushed-out pins
Connect the instrument cluster connector and make sure it seats correctly.
Operate the system and verify the concern is still present.
Is the concern still present?
J4 CHECK FOR CORRECT POWERTRAIN CONTROL MODULE (PCM) OPERATION
Disconnect all the PCM connectors.
Check for:
corrosion
pushed-out pins
Connect all the PCM connectors and make sure they seat correctly.
Operate the system and verify the concern is still present.
Is the concern still present?

Pinpoint Test K: The Brake Warning Indicator Is Never/Always On

Normal Operation
When the parking brake is applied, circuit 1309 (RD/YE) to the smart junction box (SJB) is grounded by the parking brake switch through circuit 1205 (BK). The SJB receives the ground
signal and sends the instrument cluster a message over the communication network to illuminate the brake warning indicator. When the brake fluid level is low, the brake fluid level switch
closes, the signal from the SJB on circuit 547 (LG/YE) is routed back to the SJB on circuit 512 (TN/LG). When a base brake system concern is detected, the anti-lock brake system (ABS)
module sends a signal to the instrument cluster over the communication network to illuminate the brake system warning indicator.
Possible Causes
circuit 1309 (RD/YE) open or short to ground
circuit 512 (TN/LG) open or short to ground
circuit 547 (LG/YE) open or short to ground
circuit 1205 (BK) open
parking brake switch
brake fluid level switch
SJB
ABS module
instrument cluster
PINPOINT TEST K: THE BRAKE WARNING INDICATOR IS NEVER/ALWAYS ON
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
K1 RETRIEVE THE RECORDED SMART JUNCTION BOX (SJB) DTCs FROM BOTH THE CONTINUOUS AND ON-
DEMAND SELF-TESTS
Check for recorded SJB DTCs from the continuous and on-demand self-tests.
Are any DTCs recorded?
K2 CARRY OUT THE INSTRUMENT CLUSTER INDICATOR LAMP CONTROL ACTIVE COMMAND USING THE
DIAGNOSTIC TOOL
Ignition ON.
Enter the following diagnostic mode on the scan tool: Instrument Cluster Active Command.
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Test Step
Test Step
Result / Action to Take
Yes
REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual to
continue diagnosis of the DTCs.
No
GO to J2.
Yes
GO to J4.
No
GO to J3.
Yes
INSTALL a new instrument cluster. REFER to
this section. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been
caused by a loose or corroded connector.
Yes
INSTALL a new PCM. REFER to Section 303-14. TEST the system for
normal operation.
No
The system is operating correctly at this time. The concern may have been
caused by a loose or corroded connector.
Result / Action to Take
Yes
For DTC B2479, GO to
For DTC C1189, GO to K9.
All other SJB DTCs, REFER to the Smart Junction
Box (SJB) Diagnostic Trouble Code (DTC) Index.
No
GO to K2.
Yes
GO to K3.
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Instrument Cluster (IC) in
K4 .
11/14/2009