SERVICE MANUAL UPDATE-SEC. 7 HYDRA-MATICAUTO TRANS DIAG.

SUBJECT: HYDRA-MATIC 4L60-E AUTOMATIC TRANSMISSION DIAGNOSIS

MODELS/YEARS 1993 BRAVADA

Beginning with Start of Production 1993, HYDRA-MATIC 4L60-E transmissions were built with the product changes explained in this bulletin. This information has been updated since publication of the 1993 Service Manual and should be noted accordingly. The information below as well as Figures 1, 2, 3 and 4 are being added to enhance 4L60-E diagnostic procedures in the 1993 Bravada Service Manual. Figures 5 and 6 update the charts located in Section 7Al4A of the same manual at pages 7Al4A-36 and 7Al4A-16. Be certain to familiarize yourself with these updates to properly diagnose the HYDRA-MATIC 4L60-E transmission.

The transmission electrical connector is a very important part of the HYDRA-MATIC 4L60-E operating system. Anything that interferes with the electrical connection can cause the transmission to set Diagnostic Trouble Codes and/or operate correctly.

TRANSMISSION ELECTRICAL CONNECTOR

The following items can affect the electrical connection:

0 Bent pins in the connector from rough handling during connection and disconnection

0 Wires backing away from the pins or coming uncrimped (in either the transmission or vehicle wiring harness

0 Dirt contamination entering the connector when it is disconnected

0 Pins in the connector backing out of the connector or pushed out during connection

0 Excessive transmission fluid leaking into the connector, wicking up into the vehicle wiring harness and degrading the wire insulation. The presence of transmission fluid in the transmission connector is not harmful in itself. The fluid only affects the vehicle harness wiring insulation if the fluid wicks up that far.

0 Water/moisture intrusion in the connector

0 Low pin retention from excessive connection and disconnection of the wiring harness

0 Pin corrosion from contamination

Points to remember when working with the transmission electrical connector:

0 To remove the connector, squeeze the two tabs towards each other and pull straight up (See illustration).

0 Carefully limit twisting or wiggling the connector during removal. This can bend pins.

0 DO NOT pry the connector off with a screwdriver or other tool.

0 To install the connector, first orient the pins by lining up the arrows on each half of the connector. Push the connector straight down into the transmission without twisting or angling the mating parts.

0 The connector should click into place with a positive feel and/or noise.

0 Whenever the transmission pass-thru connector is disconnected from the vehicle harness and the engine is running, multiple Diagnostic Trouble Codes will set. Be sure to clear these codes after reconnecting the pass-thru connector. Trouble Codes 59, 67 and 82 will set with key on, engine off. Trouble Codes 59, 66, 67, 73 and 82 will set with key on, engine on.

4L60-E COMPONENT RESISTANCE CHART

WIRE PASS-THRU RESISTANCE CKT COMPONENT TERMINAL COLOR PIN @ 20'C --- --------- -------- ----- --------- ----------

A RED E* 1149B 1-2 SHIFT SOLENOID 20 - 40 Ohms B GRN LT A 1222

A RED E* 1149A 2-3 SHIFT SOLENOID 20 - 40 Ohms B YEL B 1223

A RED E* 1149C 3-2 CONTROL SOLENOID 9 - 14 Ohms B WHT S 897

A PPL C 1228 PRESSURE CONTROL SOLENOID 3.5 - 8 Ohms B BLU LT D 1229

A BRN L 1227 TRANS TEMPERATURE SENSOR 2.9 - 4.0 kohms B GRA M 455

C PNK N See PSA Chart 1224 Figure 18 PRESSURE SWITCH ASSEMBLY D ORN P 1226

E BLUE DK R 1225

A RED E* 1149E TCC SOLENOID 20 - 40 Ohms B BLACK T 422A

*Spliced internally to Pin E.

Figure 3 - 4L60-E Component Resistance Chart

TECH 1 PARAMETER IN PARK AT IDLE UPSHIFTS IN UPSHIFTS IN ---------------- --------------- D4 OR D3 D2 OR D1 ----------- ----------- ENGINE SPEED 550-750 Varies Varies

TRANS OUTPUT SPEED 0 (1) Varies Varies

VEHICLE SPEED 0 Varies Varies

KICKDOWN ENABLED NO NO NO

A/B/C RNG OFF ON OFF OFF ON ON or OFF OFF-OFF or OFF OFF ON ON OFF OFF

PRNDLE SELECT Park/Neutral Drive 4 or D3 D2 or D1

COMMANDED TCC OFF (5) OFF

TCC SLIP RPM 600-750 + / -30 If Applied 0-2500 RPM

COMMANDED GEAR 1 1, 2, 3, or 4 1 or 2 (4)

1-2 SOL / 2-3 SOL ON ON ON ON or OFF ON or OFF OFF or ON OFF ON ON or OFF ON

DESIRED PCS 1.01 0 - 1.01 0 - 1.01

ACTUAL PCS 1.01 0 - 1.01 0 - 1.01

PCS DUTY CYCLE 40 - 60% 0 - 70% 0 - 70%

BRAKE SWITCH Released Released Released

4WD LOW SWITCH OFF OFF OFF

ENG COOL TEMP 85 degrees C (8) 85 degrees C (8) 85 degrees C (8) - 105 degrees C - 105 degrees C - 105 degrees C

TRANS FLUID TEMP 3O degrees C (8) 30 degrees C (8) 30 degrees C - 130 degrees C - 130 degrees C - 130 degrees C

THROTTLE ANGLE 0% 10 - 50% 10 - 50%

THROTTLE POSITION .4 -.6 V .6 - 2.5 V .6 - 2.5 V

1-2 SHIFT TIME .3 - 1.35 Sec. .3 - 1.25 Sec. .3 - 1.25 Sec. (2)(3) (2)(3) (2)(3)

ADAPTABLE SHIFT NO (3) YES NO

1-2 SHIFT ERROR 0 - 6.25 Sec. 0 - 6.25 Sec. 0 - 6.25 Sec. (2)(3) (2)(3) (2)(3)

2-3 SHIFT TIME .3 - 1.35 Sec. .3 - 1.25 Sec. .3 - 1.25 Sec. (2)(3) (2)(3) (2)(3)

1-2 ADAPT CELL 1 -5 - 10 -5 - 10 -5 - 10

1-2 ADAPT CELL 2 -5 - 10 -5 - 10 -5 - 10

1-2 ADAPT CELL 3 -5 - 10 -5 - 10 -5 - 10

A/C REQUEST OFF OFF OFF

C/C STATUS OFF OFF OFF

CALIBRATION ID Internal ID Only Internal ID Only Internal ID Only

SYSTEM VOLTS 13.6 13.6 13.6

CTR FDBK 1/2 2/3 ON ON (6) OFF OFF or ON ON or OFF ON OFF (6) ON (6)

CONT FDBK TCC OFF (6) OFF ON (6) OFF (6)

3-2 CONTROL SOL 0% 90% Above 1st Gear 90% Above 1st Gear

3-2 CONTROL FDBK OFF Oscillates ON/OFF Oscillates ON/ OFF

1. There may be a small speed reading due to vehicle vibration.

2. Zero until a shift occurs.

3. 'Yes' means the shift time is an accurate and valid number. (If shift was adaptable.)

If shift was adaptable, 'No' indicates the shift time is not accurate for one or more of the following reasons:

0 Transmission is in D2 or D1

0 There is a long shift delay

0 There is a long shift time

0 There has been a significant throttle angle change

0 Transmission is in hot mode

0 A shift starts too soon after the solenoids change states

0 Diagnostic codes are set (21, 22, 24, 28, 53, 58, 59, 72, 73, 75, 79, 81 or 82)

0 There has been a significant vehicle speed change

0 4WD lo switch is on

4. PCM will command first gear only if THROTTLE ANGLE is 100%.

5. TCC normally applies in fourth gear but may apply in D4 third gear at 100% THROTTLE ANGLE at 75 mph.

It will apply earlier in D3 third gear.

6. Should match commanded solenoid state.

7. Value will drop during a 3-2 downshift.

8. Normal operating temperature.

Figure 6 - Typical TECH 1 Data Values

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.