J - Power Lumbar Support Does Not Work Properly

Pinpoint Test J: Power Lumbar Support Does Not Work Properly

J1 - Check Ground Circuit At Pump

- Disconnect connector at front seat back pad adjusting pump.
- Using a multimeter, connect one lead of ohmmeter to circuit 57 (BK) at connector and the other lead to a known good ground.
- Read resistance.

Is resistance 5 ohms or less?

YES GO to J2.
NO SERVICE circuit 57 (BK). RESTORE vehicle. RETEST system.

J2 - Check Supply At Front Seat Back Pad Adjusting Pump

- With pump disconnected, connect one lead of voltmeter to circuit 490 (R) and the other lead to a known good ground.
- Activate seat control switch to inflate position.
- Measure voltage.

Is voltage 10.5 volts or more?

YES G0 to J7.
NO GO to J3.

J3 - Check Circuit 490 (R) At Switch

- Remove seat regulator control switch.
- Connect harness to seat regulator control switch.
- Using a voltmeter, back-probe circuit 490 (R) and connect other lead to known good ground.
- Activate switch to inflate position.

Is B+ present?

YES SERVICE circuit 490 (R). RESTORE vehicle. RETEST system.
NO GO to J4.

J4 - Check Power Supply To Seat Control Switch

- With seat regulator control switch disconnected, connect voltmeter between Circuit 517 (BK/W) and a known good ground.
- Disconnect seat regulator control switch harness

Is B+ present?

YES REPLACE seat regulator control switch. RESTORE vehicle. RETEST system.
NO GO to J5.

J5 - Check Continuity Of Circuit 517 (BK/W)

- Locate and remove circuit breaker for seat regulator control switch.
- Using an ohmmeter, connect one lead to circuit 517 (BK/W) at seat and other lead at fuse junction panel seat circuit breaker output.
- Read resistance.

Is resistance 5 ohms or less?

YES GO to J6.
NO SERVICE open in circuit 517 (BK/W). RESTORE vehicle. RETEST system.

J6 - Check Supply From Fuse Junction Panel

- Locate and remove circuit breaker 14 (20A) for seat regulator control switch.
- Connect voltmeter between known good ground and battery side of circuit breaker cavity.

Is B+ present?

YES SERVICE circuit from fuse junction panel to seat regulator control switch. RESTORE vehicle. RETEST system.
NO SERVICE supply circuit from battery to fuse junction panel. RESTORE vehicle. RETEST system.

J7 - Check Airflow At Front Seat Back Pad Adjusting Pump

- Remove front seat back pad adjusting hose from pump.
- Activate seat regulator control switch to inflate position.
- Air should be felt at pump opening.

Was air felt coming from pump opening?

YES GO to J8.
NO REPLACE pump. RESTORE vehicle. RETEST system.

J8 - Check Airflow At Seat Regulator Control Switch

- Reconnect front seat back pad adjusting hose to pump.
- Disconnect front seat back pad adjusting hose at seat regulator control switch from front seat back pad adjusting pump.
- Activate seat regulator control switch to inflate position.
- Air should be felt from open hose.

Is air felt at open hose?

YES GO to J9.
NO SERVICE front seat back pad adjusting hose. RESTORE vehicle. RETEST system.

J9 - Check System For Leaks

- Reconnect front seat back pad adjusting hose at seat regulator control switch.

In-Line Pressure Gauge Installation:

- Disconnect front seat back pad adjusting hose at front seat back pad adjuster and connect an in-line pressure gauge.
- Activate seat regulator control switch to inflate position until gauge reads 34.47 kPa (5 psi).
- System should hold pressure for three hours

After three hours, is reading 32.41 kPa (4.7 psi) or more?

YES SYSTEM OK. RESTORE vehicle. RETEST system.
NO GO to JC10.

J10 - Check Front Seat Back Pad Adjuster For Leaks

- Remove in-line pressure gauge.
- Insert hand pump into front seat back pad adjuster.
- Inflate front seat back pad adjuster to 34.47 kPa (5 psi).
- Front seat back pad adjuster should hold pressure for three hours.

After three hours, is reading 32.41 kPa (4.7 psi) or more?

YES REPLACE seat regulator control switch. RESTORE vehicle. RETEST system.
NO REPLACE front seat back pad adjuster. RESTORE vehicle. RETEST system.