With CTM
CTM Diagnostic Test ModeNOTE: CTM diagnostics are not accessible with NGS Tester.
The diagnostic test mode is used to test the CTM while the CTM is in the vehicle. While in this mode, DTCs can be retrieved and cleared and CTM inputs can be individually tested.
NOTE: Normal CTM functions are disabled while in the diagnostic test mode.
1. Entering and Exiting Diagnostic Test Mode
The diagnostic test mode is entered by shorting together the pins of the diagnostic connector, located behind the right side kick panel.
After the 3-second test, the CTM will pause for 1 second and then proceed to either the Input Test mode or DTC Output mode depending on the state of the key-in-ignition input.
The CTM returns to the normal mode when the pins of the diagnostic connector are no longer connected.
2. Operation
The diagnostic test mode is made up of the following:
^ Tone and Door Ajar Indicator Test mode.
^ DTC Output mode.
^ Input Test mode.
The Tone and Door Ajar Indicator Test mode is run immediately upon entry into the diagnostic test mode. When this is complete, the key-in-ignition input is then used to switch between the Input Test mode and the DTC Output mode. When the key is not in the ignition switch, the DTC Output mode will be active. When the key is in the ignition switch, the Input Test will be active. The Input Test mode and DTC Output mode can be switched indefinitely until the pins of the diagnostic connector are disconnected.
Tone and Door Ajar Indicator Test Mode
When the diagnostic test mode is first entered, the CTM will generate a tone and illuminate the door ajar indicator for 3 seconds if the ignition is in the RUN/ACC or RUN position. Use the following table to diagnose concerns with the warning chime and door ajar indicator.
Diagnostic Trouble Code Output Mode
When the CTM is in the normal mode of operation it is continually monitoring itself. When a concern occurs that the CTM can recognize, it is recorded.
The DTC Output mode outputs DTCs by sounding the chime. This mode is entered from the input test mode when the key is removed from the ignition switch. These DTCs may then be used to help diagnose hard faults and/or intermittent failures. Such failures will often be observed by the vehicle owner while the vehicle is on the road but may not occur when the vehicle is being repaired.
Erasing DTCs
DTCs are erased when tile diagnostic mode is exited if the ignition switch has been moved to the START position any time during the diagnostic test mode. DTCs are also erased when power is removed from the CTM.
CTM DTCs
The CTM's DTCs are 2 digits in length and are output to the operator by the sounding of the chime.
Code 21 Chart:
The first digit is output, followed by a one second pause, followed by the next digit. Each digit is made up of 1 to 9 one-second individual chime tones. The Code 21 Chart represents the output of the DTC 21.
Diagnostic Trouble Code Chart
The entire set of stored DTCs will be repeated indefinitely until either the Input Test mode is entered or the ground is removed from the diagnostic input. Refer to CTM Diagnostic Trouble Code Index. With CTM
CTM Input Test Chart:
Input Test Mode
NOTE: Several of the inputs will not operate unless the ignition is in the RUN position.
The Input Test mode individually tests the CTM inputs. It is entered from the DTC Output mode when the operator puts the key in the ignition assembly. Inputs may be tested in any order. As an input is toggled on or off, the door ajar indicator (if the ignition switch is in the RUN position) and tone outputs will be activated for 1 second for confirmation. At any time, if the key is removed from the ignition switch, the DTC Output mode will be re-entered.
Note that all CTM functions remain disabled while in diagnostic test mode. The CTM Test Chart shows all the possible inputs that can be tested for the CTM controlled interior lighting system.
1. The interior lighting system is a Central Timer Module (CTM) controlled system.
2. Verify the customer concern by operating the interior lamps.
3. Visually inspect for obvious signs of mechanical and electrical damage.
VISUAL INSPECTION CHART
Mechanical
^ Switch(es)
Electrical
^ Fuse(s)
^ Wiring harness
^ Loose or corroded connector(s)
^ Circuitry
^ Bulb(s)
4. If the concern is not visually evident, determine symptom and proceed to Symptom Chart. With CTM