1998 Chevy Tahoe I think 4X4 module

Tiny
MIKE HERMAN
  • MEMBER
  • 1998 CHEVROLET TAHOE
  • V8
  • 4WD
  • AUTOMATIC
  • 100,250 MILES
The module is located inside the vehicle under the dashuper left hand corner. It usually clicks three or four times and a lot of things happen when I start the car the next time, but not always. They are : Car will not stay running on till it warms up, the indicator lights for the four wheel drive doesn’t come on exp. 2w, 4x4auto, 4x4 high, 4x4 low but it dose change to the faction I push, It will drain the battery once in while (I have a new battery), and some times it will turn on the interior lights, the seat heaters don’t work. If it dose not click it seems as though every thing works.
Do you
have the same problem?
Yes
No
Sunday, March 21st, 2010 AT 10:30 AM

5 Replies

Tiny
DAVE H
  • EXPERT
Hello. Thanks for the doantion. Much appreciated

I need you to check it is the actual module that is clicking. Also does the module have a part # on it? There are numerous relays located under the left side of the dash. Please check it is not one of these clicking !
Was this
answer
helpful?
Yes
No
-1
Tuesday, March 23rd, 2010 AT 2:44 PM
Tiny
MIKE HERMAN
  • MEMBER
Bill

This is the actual module that is clicking The # is 15009564. And it is superseded to12577421. Do You know of any bulletins on this module?

Thank You Mike Herman
Was this
answer
helpful?
Yes
No
+1
Thursday, March 25th, 2010 AT 3:04 PM
Tiny
DAVE H
  • EXPERT
SYSTEM DIAGNOSTICS
The Transfer Case Control Module (TCCM) monitors transfer case operation along with input and output information. If TCCM self-diagnostic system senses a failure or problem in the transfer case control system, a Diagnostic Trouble Code (DTC) will be stored in TCCM memory. Diagnostic trouble code can be retrieved for diagnosis of transfer case control system.
DTC DEFINITIONS
DTC "1"
When ignition switch is in run position, TCCM tests whether RAM standby power (battery maintained power) to TCCM was lost since ignition was last turned off. When power is interrupted to TCCM (pin No. 6), TCCM stores loss of RAM standby power and sets DTC "1". If DTC "1" is present, check Orange wire circuit between TCCM and fuse block. Repair circuit as necessary. If Orange wire circuit is okay, replace TCCM.
DTC "2"
During electronic shifting, TCCM checks motor/encoder for normal operation. If motor/encoder does not function properly, TCCM stores motor/encoder failure DTC "2". If DTC "2" is present, check circuits between TCCM and motor/encoder. If circuits are okay, replace motor/encoder. If circuits are repaired, perform TRANSFER CASE FUNCTIONAL TEST.
DTC "3"
Each time electronic shift motor is turned on or off, TCCM tests whether motor functions properly. If motor does not function properly, TCCM stores motor link circuit failure DTC "3". Shift select buttons will blink to alert driver of problem. If DTC "3" is present, check circuits between TCCM and electric shift motor. If circuits are okay, replace electric shift motor. If circuits are repaired, perform TRANSFER CASE FUNCTIONAL TEST.
DTC "4"
Each time ignition is turned on, TCCM tests memory, program and internal system to ensure TCCM is operating properly. If fault is detected in TCCM, it stores a RAM/ROM memory failure DTC "4". If DTC "4" is present, replace TCCM.
RETRIEVING DTCS
NOTE:Diagnostic Trouble Codes (DTCs) are displayed on 3 transfer case shift select buttons. When proper conditions are met, select buttons will blink to indicate DTC from "1" to "4".

Turn ignition off for at least 6 seconds. Locate DLC near right side of steering column. Install jumper wire between diagnostic pigtail (Orange wire at DLC terminal No. 13) and ground.
Turn ignition to run position (engine off). Observe shift select buttons. If all shift select buttons blink once at same time then stop, no DTCs are stored. If only one code is stored in TCCM memory, that code will blink repeatedly, with a 3 second delay between sequences. If more than one code is present, next code will flash after a 3 second delay, then sequence will repeat. Count number of blinks for each code. See Fig. 1.
Write down all DTCs. After retrieving DTCs. Clear TCCM memory and repeat procedure. See CLEARING DIAGNOSTIC TROUBLE CODES. If DTCs return, perform appropriate test. See DTC DEFINITIONS under SELF-DIAGNOSTIC SYSTEM.
Fig. 1: Reading Diagnostic Trouble Code
Courtesy of GENERAL MOTORS CORP.
CLEARING DIAGNOSTIC TROUBLE CODES
NOTE:DTCs will not be cleared if 20-amp T-case fuse is not removed for at least 30 seconds.

Turn ignition off. Remove T-CASE (20-amp) fuse from fuse block. Wait at least 40 seconds and reinstall fuse. Cycle ignition on and off 5 times. All DTCs will be cleared from TCCM memory.
Was this
answer
helpful?
Yes
No
+9
Thursday, March 25th, 2010 AT 5:44 PM
Tiny
GAVIN2
  • MEMBER
Dave h. You seem very knowledgeable in chevy 4wd. I have a 99 chevy k1500 push button 4wd. No 4wd. Tcase dosent engage front driline, electric acuator doesnt engage, no stored trouble codes, lights work on pushbuttons work. Would you assume the tccm module is bad?
Thanks
Was this
answer
helpful?
Yes
No
Monday, October 3rd, 2016 AT 10:23 PM
Tiny
ANNE CHRISTINA JEREMY
  • MEMBER
We have a 1998' 'Holden' badged Chevy suburban that we are unable to electronically get into 4wd. Like you Gavin, no stored trouble codes; lights for 2hi/4hi/4lo push button select light up after turning key on, (to show lights function), before remaining in steady 2 hi. We have ruled out other problems as front axle actuator; motor encoder, and wiring to it, as it shows good voltage. We also took our vehicle to a professional yard that only works on Chevies, who used both a 'Tech 2' and another even more expensive scan tool, commenting that his machines couldn't read our system, to get a true diagnosis, only stating that when 4wd hi and lo were activated, he could only get a signal to the TCCM. (No further info). When we try to activate 4wd, we appear to get a clicking sound, coming from inside the TCCM likely we think, one of the two small relays there. We have also tried to check voltages on the harness wiring from pushbuttons 4wd select, going into TCCM and these appear good, visually and getting voltage. We have prev had issues with the finicky wiring in push button select, with 4hi/4lo lamps not turning on, (but they have been easily fixed, lamp wise) but do remain unsure whether something as simple as a dud 4wd select unit could still be the cause for all our problems; or just the TCCM even though there is an absence of fault code e.G. Like a DTC 4. Like Gavin above, can the absence of a TCCM fault code still not rule out a bad TCCM? We opened this unit up as well, and saw no evidence of anything being burnt out; or corrosion etc. The pins going into the TCCM looked also very clean and shiny. Rather than spend $500 getting a replacement, is there another way of checking the TCCM for issues? I have some pics of the TCCM eg relays. Have noted on other forums the general confusion others have in determining where there 4wd relay is located. So even if no one can help me, perhaps my small contribution might offer someone something.
Was this
answer
helpful?
Yes
No
+1
Saturday, November 5th, 2016 AT 9:05 PM

Please login or register to post a reply.

Recommended Guides