DTC 1744 1998 AX4N

P1744 / TCC / Excessive slip detected. / Excessive slip detected during full TCC engagement. / Torque converter disengaged. EPC pressure at minimum. May activate MIL. / Pinpoint Test C

PINPOINT TEST C: TORQUE CONVERTER CLUTCH (TCC) SOLENOID

NOTE: Refer to the Transaxle Internal Harness illustration preceding these pinpoint tests.

NOTE: Refer to the Transaxle Harness Connector illustration preceding these pinpoint tests.

C1 AX4N ELECTRONIC DIAGNOSTICS

· Check to make sure transaxle harness connector C168 is fully seated, terminals are fully engaged in connector and in good condition before proceeding.

· Connect Rotunda New Generation Star Tester 007-00500 or equivalent.

· Perform KOEO Test until Continuous Memory DTCs have been displayed.

· Enter Output Test Mode (OTM). Refer to Special Test Modes.

· Select the mode ALL ON.

· Press START to turn outputs ON.

· Push STOP to turn outputs OFF.

Does vehicle enter OTM?

Yes / No
REMAIN in OTM. GO to C2 . / PRESS START. If vehicle does not enter OTM, REFER to Powertrain Control/Emissions Diagnosis Manual.

C2 CHECK ELECTRICAL SIGNAL OPERATION

CAUTION: Do not pry on connector. This will damage the connector and could result in a transaxle concern. Press button and pull up on the transaxle harness connector.

· Disconnect the transaxle harness connector C168 .

· Using a mirror, inspect both ends of connector for damage or pushed out pins, corrosion, loose wires and missing or damaged seals.

· Connect a voltmeter positive test lead to VPWR circuit C168 and negative test lead to solenoid circuit of transmission transaxle harness connector C168 .

· Place voltmeter on 20 volt scale.

· While observing voltmeter, press start and stop to cycle solenoid output on and off.

Does the suspected solenoid output voltage change at least 0.5 volt?

Yes / No
GO to C5 . / GO to C3 .

C3 CHECK CONTINUITY OF SOLENOID SIGNAL AND VPWR HARNESS CIRCUITS

· Turn ignition switch off.

· Disconnect transaxle harness connector C168 .

· Disconnect powertrain control module . Inspect for damaged or pushed out pins, corrosion, or loose wires.

· Install Rotunda 104-Pin Breakout Box 014-00950 or equivalent. Leave powertrain control module disconnected.

· Measure resistance between PCM Signal Test Pin 54 at breakout box and signal pin at transaxle harness connector C168 .

· Measure resistance between PCM Signal Test Pins 71/97 at breakout box and VPWR pin at transmission vehicle harness connector C168 .

Is each resistance less than 5.0 ohms?

Yes / No
GO to C4 . / SERVICE OPEN circuit(s). REMOVE breakout box. RECONNECT all components. REPEAT Quick Test.

C4 CHECK SOLENOID/HARNESS FOR SHORTS TO POWER AND GROUND

· Make sure Rotunda 104-Pin Breakout Box 014-00950 or equivalent is installed and powertrain control module disconnected.

· Make sure transaxle harness connector is disconnected.

· Measure resistance between PCM Signal Test Pin 54 and test Pins 71/97 at the breakout box.

· Measure resistance between PCM signal output Pin 54 and test Pins 24/51/76/77/103 and 91 at breakout box and chassis ground.

Is each resistance greater than 10,000 ohms?

Yes / No
GO to C5 . / SERVICE SHORT circuit(s). REMOVE breakout box. RECONNECT all components. REPEAT Quick Test.

C5 TRANSAXLE FUNCTIONAL TEST

CAUTION: Do not pry connector. This will damage the connector and could result in a transaxle concern. Press button and pull up on the transaxle harness connector.

· Disconnect transaxle harness connector C168 .

· Install tester to transaxle connector.

· Using tests described under Transmission Tester Instructions.

§ Perform TCC solenoid voltage test as described under Rotunda Transmission Tester.

NOTE: LED will turn green when solenoid activates and turns OFF when deactivated. LED will turn red if an activated solenoid/harness is shorted to B+. LED will remain OFF if an activated solenoid/harness is shorted to ground or no continuity (open circuit).

Does TCC (LED green) activate when tester switch is pressed?

Yes / No
GO to C6 / GO to C7

C6 TRANSAXLE DRIVE CYCLE TEST

· Connect powertrain control module.

· Perform Transaxle Drive Cycle Test as described under On-Board Diagnostics with NGS.

· While in second gear press the TCC switch.

Does TCC activate (LED green)? Does engine rpm drop?

Yes / No
REPLACE powertrain control module . ERASE all DTCs. Road test and run self test. If symptoms are still present, REFER to Diagnosis by Symptom—Torque Converter concerns. / GO to C7

C7 CHECK RESISTANCE OF SOLENOID/HARNESS

NOTE: Refer to AX4N transmission tester for terminal locations.

· Set Bench/Drive switch to BENCH mode.

· Rotate Gear Select switch to OHMS CHECK position.

· Connect ohmmeter negative lead to TCC jack and positive lead to VPWR jack on tester.

· This is to test TCC.

· Record resistance. Resistance should be between 13-24 ohms.

Is the resistance within specifications?

Yes / No
GO to C8 / Internal harness or solenoid may be damaged. GO to C9

C8 CHECK SOLENOID/HARNESS FOR SHORT TO GROUND

· Check for continuity between BAT- jack (engine ground) and appropriate jack with an ohmmeter or other low current tester (less than 200 milliamps).

Solenoid / Tester Jack
TCC / TCC VPWR

·

· Connection should show infinite resistance (no continuity).

Is there continuity?

Yes / No
GO to C9 / REFER to Hydraulic/Mechanical Diagnostic Routines in Diagnosis by Symptom to diagnose torque converter clutch concerns.

C9 AX4N INTERNAL ELECTRONIC DIAGNOSTICS

· Drain transaxle fluid.

· Remove transaxle side pan.

· Check that the internal harness connector is fully engaged on the TCC solenoid assembly.

· Check that the internal harness connector terminals are fully seated in the connector.

· Inspect the connector for damage.

Are the connector/terminals in good condition?

Yes / No
GO to C10 / SERVICE as required.

C10 CHECK INTERNAL AX4N HARNESS (CONTINUITY)

CAUTION: Do not probe into connector terminals. This will damage the connector and could result in a transaxle concern.

· Disconnect the internal harness from the solenoid assembly. (TCC wire connector).

· Connect positive lead from an ohmmeter to tester TCC jack and the negative lead at the brown wire at the TCC connector.

· Record resistance. Resistance should be less than 0.5 ohm.

· Next, connect the positive lead from an ohmmeter to the tester VPWR jack and the negative lead to the green wire of the TCC connector.

· Record resistance.

Is each resistance less than 0.5 ohm?

Yes / No
GO to C11 / REPLACE internal harness. GO to C12

C11 CHECK INTERNAL AX4N HARNESS (SHORTS TO GROUND)

· Check for continuity between BAT- jack (engine ground) and the appropriate wire with an ohmmeter or other low current tester (less than 200 milliamps).

Solenoid / Wire
TCC
VPWR / Brown
Green

·

· Connection should not show continuity (infinite).

Is there continuity?

Yes / No
REPLACE internal harness. GO to C12 / GO to C12

C12 CHECK SOLENOID RESISTANCE

· Check solenoid resistance by connecting an ohmmeter to the terminals of the TCC solenoid.

· Record resistance.

· Resistance should be between 13-24 ohms.

Is resistance within specifications?

Yes / No
GO to C13 / REPLACE TCC solenoid.

C13 CHECK SOLENOID FOR SHORT TO GROUND

· Check for continuity between BAT- jack (engine ground) and each solenoid terminal on the TCC with an ohmmeter or other low current tester (less than 200 milliamps).

Solenoid / Terminal
TCC / +/-

·

· Connection should show infinite resistance (no continuity).

Is there continuity?

Yes / No
REPLACE TCC solenoid. / REFER to Hydraulic/Mechanical Diagnostic Routines in Diagnosis by Symptom.