Section 3
SECTION 3 (Seat Shuts Off Less Than 40 Seconds, But More Than 5 Seconds)1. Follow the spread terminal fix procedure listed in Section 5. If this has already been performed and in Step 3 in Section 1 has lead you back to this procedure, proceed to Step 2.
2. If CCS continues to be inoperable with a B272C/D code, determine if an over-temp DTC is present (B2729, B2730, B272A, B272B).
a. If there is an over-temp DTC present, then continue to Step 3.
b. If there is no over-temp DTC present, then continue to Step 5.
c. If CCS is now operable, then repower the SRS and return vehicle to customer.
3. Are any of the Temperature PIDS reading between 200° F (93° C) and 400° F (204° C) at room temperature conditions (when heat mode has not been on for 5 minutes), or is one TED reading 10° higher than the other TED?
a. If readings are hotter than room temperature, go to Step 4.
b. If TED temperatures between Back and Cushion are 100 different, go to Step 12.
c. If reading correctly then, proceed to Step 5.
4. Check for short to ground or voltage in the thermistor circuit. (As shown on TED connector (C3034 - Driver Back, C3035 - Driver Cushion, C3039 - Passenger Back, or C3040 - Passenger Cushion). (Figure 1)
a. Looking into the harness side of the TED connector (C3034 - Driver Back, C3035 - Driver Cushion, C3039 - Passenger Back, or C3040 - Passenger Cushion) the voltage should read 5v +/- 1.5v present at Pin 3 with the ignition on.
(1) If no, then unplug DCCSM and check if harness side Pin 3 is shorted to ground.
(2) If yes, fix the wiring, if no replace the DCCSM.
b. Checking TED assembly connector, is resistance across Pins 2 and 3 greater than 1000 ohms?
(1) If yes, go to Step 5.
(2) If no, then replace TED. (Figure 2)
5. Is one of the TED PID readings less than 0° F (-18° C) or greater than 400° F (204° C)?
a. If yes, go to Step 6.
b. If no, go to Step 7.
6. Ensure the module is producing voltage to the thermistor circuit of the TED, checking the harness side of TED connector (C3034 - Driver Back, C3035 - Driver Cushion, C3039 - Passenger Back, or C3040 - Passenger Cushion) the voltage should be 5v +/- 1.5v present at Pin 3 with ref to Pin 2.
a. If no voltage to thermistor is present at TED, then ensure the harness is not damaged by checking the voltage at the module Connector C3265A-Pins 13, 14, 15, 16 (DCCSM Connector C3265B must remain plugged in). If no voltage is present at DCCSM, then replace DCCSM, otherwise replace the harness. Verify system now functions and return vehicle to customer.
b. If the correct voltage is present to the thermistor, then replace the TED assembly. Verify system now functions and return vehicle to customer.
7. Cycle ignition and enter into high cool mode. Does failure still occur?
a. If no, proceed to Step 8.
b. If yes, proceed to Step 13.
8. Ensure voltage is getting to the suspect TED. Enter heat mode and back probe Pin 6 of the TED connector.
NOTE
DO NOT LEAVE IN HEAT MODE FOR OVER 1 MINUTE
a. If voltage is not getting to the suspect TED, proceed to Step 9.
b. If voltage is getting to the suspect TED, replace TED.
9. Ensure voltage is coming out of the module by back probing the suspect pin on C3265B of the module. (Figure 3)
^ Driver Cushion - Pin 9
^ Driver Backrest - Pin 8
^ Passenger Cushion - Pin 11
^ Passenger Backrest - Pin 22
a. If no voltage is coming out of the module, then replace the module and continue to Step 13.
b. If the correct voltage is coming out of the module, then continue to Step 10.
10. Disconnect DCCSM C3265B. Check for an open circuit (resistance greater than 5 ohms) from the TED that is reading the cold temperature to the CCSM (C3265B). If no open circuit is found, then continue to Step 11. (Figure 4)
11. With DCCSM C3265B disconnected, check for a short circuit (short to voltage is less than 0.2 volts, short to ground is resistance less than 10,000 ohms) in the wiring from the TED that is not reading the over-temp to the CCSM. If no short circuit is found, then replace the TED. (Figure 5)
12. Is the resistance on the thermistor circuit at the TED connector (C3034 - driver back, C3035 - Driver Cushion, C3039 - Passenger Back, or C3040 - Passenger Cushion) between 2.7 K ohms (proper value @ 65° F) (18° C) to 1.86 K ohms (proper value @ 80° F) (27° C) at ambient (room temperature)?
a. If no, then replace the TED that is outside the resistance range specified above, assuming the TED is at room temperature, and proceed to Step 12.
b. If yes, then proceed to Step 13.
13. If CCS continues to be inoperable with a B272C/D code and:
a. Time to failure is different than before, then start new diagnosis from Step 4 Section 1.
b. Time to failure is not different than before, then continue to Step 14.
c. If CCS is now operable, then repower the SRS and finish other repairs as needed and return vehicle to customer.
14. Check for any kinks or obstructions of the ducting from the fan to the TED. (Figures 6 and 7)
a. If there is a kink or obstruction of the ducting, repair as needed and continue to Step 15.
b. If there are no kinks or obstructions of the ducting then, continue to Step 16.
15. If CCS continues to be inoperable with a B272C/D code and:
a. Time to failure is different than before, then start new diagnosis from Step 3 in Section 1.
b. Time to failure is not different than before, then continue to Step 16.
c. If CCS is now operable, then repower the SRS and finish other repairs as needed and return vehicle to customer.
16. Check if the seat back/cushions are damaged or the scrim (Figures 8 and 9) has been obstructed or damaged or bunched in the cushion blocking air flow from the TED.
a. If the cushion or scrim is damaged or bunched or is incorrect, then repair or replace the damaged cushion/scrim and continue to Step 17.
b. If the cushion or scrim is not damaged or bunched and is correct for a climate control seat, then replace the TED and continue to Step 17.
17. If CCS continues to be inoperable with DTC B272C/D code, start a new diagnosis from Step 3 in Section 1 of this TSB. If CCS in now operable, repower the SRS, and return vehicle to customer.