13 minute read
1–2 General Troubleshooting of Performance Complaints
Make the following general checks before beginning specific troubleshooting, removing the transmission, or removing attached components.
• Are wheel chocks in place? • Are there active diagnostic codes? • Is the shift selector in N (Neutral) to allow starting the engine? • Is the battery properly connected and charged? • Is the transmission fluid level correct? • Is voltage to the TCM correct? • Are engine parameters correct for the transmission? • Is the engine properly tuned? • Is fuel flow to the engine correct? • Is air flow to the cooler and radiator unrestricted? • Is the driveline properly connected? • Are there signs of fluid leakage under the vehicle? What is the origination point? • Are hydraulic connections correctly made and not leaking? • Has vehicle acceleration from a stop changed? • Are electrical connections correctly made? • Are there any other obvious vehicle or transmission problems?
After making these general checks use the various sections of this manual to isolate the listed problems. The following charts address specific vehicle complaints. Some complaints involve diagnostic codes, so all troubleshooting checks should involve checking the system for diagnostic codes.
T able 1–1.Troubleshooting Performance Complaints Suggested Remedy
P ossible Cause Select N (Neutral) and restart
Lever shift selector not in neutral or Park Recharge battery Reconnect battery Repair vehicle starter circuit Replace NSBU switch (see Paragraph 3–2 b ) Adjust NSBU switch (see Paragraph 3–2 a ) Repair wiring
Dead battery Disconnected battery F aulty starter circuit F aulty NSBU switch Misadjusted NSBU switch F aulty wiring in vehicle neutral start circuit Properly install electrical connector
Electrical connector not properly seated on NSBU switch INSTALL DIAGNOSTIC TOOL TO DETERMINE IF DTC IS PRESENT
TCM HAS LOGGED A DTC Replace relay or repair circuit
F aulty CHECK TRANS light, relay, or circuit.
Problem VEHICLE WILL NOT START (ENGINE WILL NOT CRANK) CHECK TRANS LIGHT WILL NOT GO OUT AT START-UP
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy
P ossible Cause
Problem Check input power to the TCM and correct if necessary
Intermittent power to TCM
CHECK TRANS LIGHT FLASHES INTERMITTENTLY Repair vehicle wiring
F aulty vehicle wiring Repair wiring
Loose wiring to CHECK TRANS light Repair ground circuit
F aulty or incorrect ground wire attachment Repair Circuit 125
Intermittent opening in Circuit 125 Replace light bulb or socket
F aulty light bulb or socket Repair wiring(see Troubleshooting Manual TS3192EN)
Incorrect wiring to and from CHECK TRANS light bulb Repair vehicle wiring Repair Circuit 125
F aulty vehicle wiring Circuit 125 open
NO CHECK TRANS LIGHT AT IGNITION
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy
P ossible Cause
Problem Reduce engine rpm (it may be necessary to reselect N eutral also, and then D or R ) Add fluid to proper level(refer to Mechanic’s Tips MT3190EN)
Engine rpm too high Low fluid level
TRANSMISSION WILL NOT SHIFT TO FORWARD OR REVERSE (STAYS IN NEUTRAL) Refer to Mechanic’s Tips MT3190EN
Throttle position sensor or linkage is not functioning properly Correct engine throttle signal
F aulty throttle signal from engine Repair shift selector or adjust linkage
Shift selector is not functioning properly Repair or replace speed sensor(s) or circuitry (see Paragraph 6–3)
Speed sensor(s) not functioning properly Repair transmission
Mechanical failure to C5 clutch Repair transmission
Mechanical failure in transmission torque converter, shafts, or planetaries Repair transmission Correct circuit wiring
Low pressure F aulty wiring in TCM Input/Output function circuits
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy
P ossible Cause
Problem Repair quick-to-neutral circuit
Auto-neutral for PTO circuit (input function) faulty
TRANSMISSION WILL NOT STAY IN FORWARD OR REVERSE Low fluid Adjust fluid level Leaking at solenoid assembly Rebuild solenoid assembly (refer to transmission Service Manual SM3191EN) Low pressure Repair transmission F aulty solenoid—leaking Replace solenoid (see Paragraph 6–9 c , d , e ) Correct engine problem, see Engine Service Manual
Low engine power
TRANSMISSION WILL NOT MAKE A SPECIFIC SHIFT Inspect cooling system and fluid level Repair circuit or replace speed sensor(s) Have OEM reset to correct setting Check for temperature reading which inhibits shifts
Extreme fluid temperature F aulty speed sensor/circuit Incorrect engine parameters F aulty temperature sensor/circuit Install correct calibration Repair shift selector
Incorrect calibration F aulty or misadjusted shift selector
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy Adjust engine idle speed (refer to Vehicle Service Manual) Refer to Mechanic’s Tips MT3190EN and/or T roubleshooting Manual TS3192EN Replace C1 piston housing Rebuild transmission and adjust clearances Install correct calibration Repair or replace tachometer Calibrate electronic speedometer Repair circuit or replace speed sensor (refer to Troubleshooting Manual TS3192EN) Change transmission fluid and filter T ighten speed sensor retaining bracket bolt
P ossible Cause Engine idle speed too fast (neutral to range shift) F aulty throttle sensor/circuit F aulty or sticking bleed ball in C1 position housing Excessive clutch running clearance Incorrect shift calibration for vehicle Instrument panel tachometer incorrect Incorrectly calibrated electronic speedometer F aulty speed sensor/circuit Degraded fluid Loose speed sensor
Problem TRANSMISSION DOES NOT SHIFT PROPERLY (ROUGH SHIFTS, SHIFTS OCCURRING AT TOO LOW OR TOO HIGH SPEED)
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy Correct fluid level Drive vehicle until shift adaptives are converged Have OEM verify engine parameters that may affect transmission performance Repair transmission Check wiring harnesses and connectors (see T roubleshooting Manual TS3192EN) T ighten output flange bolt or replace speed gear Overhaul control valve body assembly Repair or replace trim solenoids (see P aragraph 6–9) Install correct calibration
P ossible Cause Incorrect fluid level Shift adaptives not converged Engine parameters not correct Low main pressure Intermittent problems Loose or damaged speed gear Sticking valves in control valve body Leaking trim solenoids Incorrect calibration
Problem TRANSMISSION DOES NOT SHIFT PROPERLY (ROUGH SHIFTS, SHIFTS OCCURRING AT TOO LOW OR TOO HIGH SPEED) (cont’d)
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy
P ossible Cause ABNORMAL ACTIVITIES OR RESPONSES
Problem Adjust to correct idle speed
Engine idle speed too high
Excessive Creep in First and Reverse Gears
A . Rebuild C1 clutch (refer to transmission Service Manual) Rebuild C3 clutch assembly (refer to transmission Service Manual SM3191EN) Adjust TPS linkage for proper stroke (refer to Mechanic’s Tips MT3190EN)
— —T ighten loose bolts or connections Install correct calibration
C1 clutch failed or not released
B .V ehicle Moves Forward in Neutral C3 clutch failed or not released
C .V ehicle Moves Backward in Neutral TPS Adjustment: v erstroke —O
EXCESSIVE FLARE — ENGINE OVERSPEED ON FULL- THROTTLE UPSHIFTS Loose — Incorrect calibration Add fluid to proper level(refer to Mechanic’s Tips MT3190EN) Rebuild control valve body assembly See Low Pressure section
Incorrect fluid level Sticking valves in control valve body assembly Low main pressure
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy Repair or replace trim solenoids (see P aragraph 6–9) See speed sensor DTCs Overhaul transmission (refer to transmission Service Manual SM3191EN)
P ossible Cause
Problem Leaking trim solenoids Erratic speed sensor signal
EXCESSIVE FLARE — ENGINE OVERSPEED ON FULL- THROTTLE UPSHIFTS (cont’d) Piston seals leaking or clutch plates slipping in range involved RANGE CLUTCH TROUBLESHOOTING SECTION
Install correct calibration Adjust or replace throttle position sensor (refer to Mechanic’s Tips MT3190EN) See speed sensor DTCs Correct fluid level (refer to Mechanic’s Tips MT3190EN) Refer to transmission Service Manual SM3191EN Inspect torque converter clutch system wiring, pressure, and controls; repair as necessary (refer to transmission Service Manual SM3191EN)
Incorrect calibration Throttle position sensor out of adjustment or failed Incorrect speed sensor readings Incorrect fluid level
EXCESSIVE SLIPPAGE AND CLUTCH CHATTER Main pressure low TCC clutch not applied
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy Inspect control module gasket, C1 clutch plates, and piston and rotating seals; replace/rebuild as necessary (refer to transmission Service Manual SM3191EN) Inspect control module gasket, C2 clutch plates, and piston and rotating seals; replace/rebuild as necessary (refer to transmission Service Manual SM3191EN)
P ossible Cause C1 clutch slipping, leaks at splitline g asket, leaks at rotating clutch seals, leaks at piston seals, C1 clutch plates w orn C2 clutch slipping, leaks at splitline g asket, leaks at rotating clutch seals, leaks at piston seals, C2 clutch plates w orn Inspect C3 clutch plates and piston seals; replace/rebuild as necessary (refer to transmission Service Manual SM3191EN)
C3 clutch slipping, leaks at piston seals, C3 clutch plates worn Inspect C4 clutch plates and piston seals; replace/rebuild as necessary (refer to transmission Service Manual SM3191EN)
C4 clutch slipping, leaks at piston seals, C4 clutch plates worn Inspect C5 clutch plates and piston seals; replace/rebuild as necessary (refer to transmission Service Manual SM3191EN)
C5 clutch slipping, leaks at piston seals, C5 clutch plates worn
Problem Ranges 1, 2, 3, 4 Only A . Ranges 4, 5 Only B . Ranges 3, 5, R Only C. Range 2 Only D. Ranges 1, R Only E.
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy
P ossible Cause LOW PRESSURE SECTION
Correct fluid level (refer to Mechanic’s Tips MT3190EN)
Incorrect fluid level Clean or replace oil suction filter element (refer to Paragraph 6–8)
Plugged or faulty suction filter Overhaul front support assembly (refer to transmission Service Manual SM3191EN)
Main pressure regulator valve sticking Repair or replace solenoids (see P aragraph 6–9 )
Leaking solenoids in control valve body assembly Overhaul front support assembly (refer to transmission Service Manual SM3191EN)
Stuck or sticking lube regulator valve Check spring and replace if necessary (refer to transmission Service Manual SM3191EN)
Main pressure regulator valve spring weak, broken, or missing Replace or rebuild control module assembly. Care should be taken when removing and labeling shift springs (refer to transmission Service Manual SM3191EN)
Control module body leakage (separator plate not flat, separator plate gasket leakage, loose control valve body bolts) Repair or replace gauge
F aulty or incorrect fluid pressure gauge
Problem Low Main Pressure in A. All Ranges
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy Replace or rebuild oil pump (refer to transmission Service Manual SM3191EN) Check suction circuit for leaking seal, g asket, or mating surface See SM3191EN for procedure to replace seals that are causing low pressure in a particular range Correct fluid level (refer to Mechanic’s Tips MT3190EN) Change filter(refer to Mechanic’s Tips MT3190EN) Change filter Check other pressures (above items); also check control module mounting bolts; lubrication valve and spring (refer to transmission Service Manual SM3191EN); converter housing to separator plate gasket Check for kinks, leakage; reroute or replace lines as necessary Clean or replace regulator valve
P ossible Cause Oil pump worn or damaged Leak in suction circuit
Problem Low Main Pressure in A. All Ranges (cont’d) Seal leak Incorrect fluid level
Main Pressure Low in Specific B. Ranges, Normal Pressure in Other Ranges Low Lubrication Pressure C. Plugged suction filter Plugged cooler circuit filter Excessive internal fluid leakage Cooler lines restricted or leaking Lubrication regulator valve sticking
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy Clean or replace converter relief valve Clean or replace cooler Repair or replace gauge Select D (Drive) Add fluid to proper level(refer to Mechanic’s Tips MT3190EN) Replace torque converter Replace torque converter (refer to transmission Service Manual SM3191EN)
P ossible Cause
Problem Converter relief valve sticking
Low Lubrication Pressure (cont’d) C. Cooler plugged F aulty gauge Not in gear Low fluid level, aerated fluid
ABNORMAL STALL SPEEDS (Stall In First Range — Fifth Range) High Stall Speeds A. F aulty torque converter Incorrect torque converter Refer to TS3192EN Electronic T roubleshooting
Clutch pressure low Rebuild C1 or C5 clutch (refer to transmission Service Manual SM3191EN)
C1 or C5 clutch slipping. Note: Use the diagnostic tool to check turbine speed Confirm proper engine match
Higher power engine
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy
P ossible Cause Refer to Vehicle Engine Manufacturer’s Manual or Vehicle Service Manual
Engine not performing efficiently (may be due to plugged or restricted injectors, high altitude conditions, dirty air filters, out of time, throttle linkage, electronic engine controls problem) Replace converter assembly (refer to transmission Service Manual SM3191EN) Compare lugback vs. static stall speed Install correct torque converter (refer to transmission Service Manual SM3191EN)
Stall speeds of 33 percent of normal implies freewheeling stator Engine smoke controls Incorrect torque converter
Problem Low Stall Speeds B. Adjust fluid to proper level, check for defective pump (refer to MT3190EN) Remove air flow obstruction
Aerated fluid — incorrect fluid level
O VERHEATING IN ALL RANGES Air flow to cooler obstructed Correct overheat situation (refer to Vehicle Service Manual)
Engine overheat Replace gauge and/or sending unit
Inaccurate temperature gauge or sending unit
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy Replace Pressure Switch Manifold (PSM) or internal harness (refer to Paragraphs 6–9) See vehicle OEM for specifications Check for plugged cooler, lines too small, collapsed hose, too many elbows in circuit Connect cooler lines properly (oil and water should flow in opposite directions) Remove restrictions, clean or replace lines (refer to Vehicle Service Manual)
P ossible Cause
Problem Inaccurate sump temperature sensor
O VERHEATING IN ALL RANGES (cont’d) Inadequate cooler sizing Excessive cooler circuit pressure drop T ransmission cooler lines reversed Fluid cooler lines restricted Replace or repair converter assembly (refer to transmission Service Manual SM3191EN) Note: Stuck stator will not allow cool down in neutral
T orque converter (wrong converter, no torque converter clutch, stuck stator, or slipping stator) Overhaul transmission (refer to transmission Service Manual SM3191EN)
Cooler flow loss due to internal transmission leakage
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy
P ossible Cause T ighten cap, replace if necessary
Dipstick loose Drain to proper level(refer to Mechanic’s Tips MT3190EN)
Fluid level too high Add fluid to proper level Clean or replace breather (refer to transmission Service Manual SM3191EN) Drain and replace fluid. Locate and fix source of additional fluid (refer to Mechanic’s Tips MT3190EN). Replace seals or dipstick Calibrate dipstick(refer to Mechanic’s Tips MT3190EN)
Fluid level too low Breather stopped up — clogged Fluid contaminated with foreign liquid Dipstick or fill tube seal worn Incorrect dipstick marking Add fluid to proper level(refer to Mechanic’s Tips MT3190EN) Replace oil suction screen canister (refer to transmission Service Manual SM3191EN) Replace filter (refer to Paragraph 6–8)
Low fluid level Air leak in oil suction screen canister Clogged suction filter
Problem FLUID COMES OUT OF THE FLUID FILL TUBE AND/OR BREATHER NOISE OCCURRING INTERMITTENTLY (BUZZING)
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy
P ossible Cause Correct fluid level (refer to Mechanic’s Tips MT3190EN)
Aerated fluid causes noisy pump See Service Manual SM3191EN
Low main pressure causes main regulator v alve to oscillate
Problem NOISE OCCURRING INTERMITTENTLY (BUZZING) (cont’d) Install new lip-type seal in rear of transmission housing (refer to transmission Service Manual SM3191EN) (see Paragraph 6–6) Replace flange
F aulty or missing seal at output flange Machine lead on output flange seal surface
LEAKING FLUID (TRANSMISSON OUTPUT) Repair or replace cover Replace flange
Rear cover porosity Flange worn at seal surface When replacing seal, refer to Paragraph 6–6
Insufficient sealant around seal OD Replace output bolt sealing washer
Damaged or missing output bolt washer seal Replace and/or torque output flange bolts (see Paragraph 6–1)
Damaged, missing, or loose output flange bolt
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy Replace front seal (refer to Paragraph 6–10)
P ossible Cause Front seal leaks
Problem TRANSMISSION INPUT Replace manifold gasket(refer to Paragraph 6–5)
Manifold gasket leaks Replace bolt seals
Front support bolt seals leaking Converter leaks Check converter seals, cracked converter pump tangs, converter cover, or converter housing porosity; replace parts as required (refer to transmission Service Manual SM3191EN) Spin-on filter leaking Replace filter Replace or torque main pressure plug
Main pressure plug leak Rebuild and repair pump
Pump bushing shows excessive wear
T able 1–1.Troubleshooting Performance Complaints (cont’d) Suggested Remedy Change fluid and install new filters(refer to Mechanic’s Tips MT3190EN) Check cooling system for restrictions and proper capacity Use recommended fluid (refer to Mechanic’s Tips MT3190EN) Overhaul transmission (refer to transmission Service Manual SM3191EN)
P ossible Cause F ailure to change fluid and filters Excessive heat Substandard fluid Clutch/transmission failure
Problem DIRTY FLUID
