Pinpoint Test A: Heated Seat Tests

1. Using the manufacturer approved diagnostic system, check the climate control system for related DTCs (where possible)

Are any heated seat DTCs set?

• Yes: Perform the relevant corrective actions. Clear the DTCs and retest. If the fault persists, GO to  A2.
• No: GO to  A2.

On full power the seat should be hot to touch

1. If necessary, operate the vehicle air conditioning on full for 10 minutes to reduce the temperature of the vehicle interior
2. Operate the heated seats on full power

Do the heated seats operate correctly?

• Yes: Using the manufacturer approved diagnostic system, clear the DTCs (where possible) and retest. If the operation of the heated seats is correct no further action is necessary
• No: GO to  A3.

1. Refer to the appropriate system wiring diagrams and the Seat Heater Mat Application Chart (see above) to identify the connector
2. Disconnect the connector
3. Refer to the appropriate system wiring diagrams and check the heated seat element circuit for short circuit to ground

Is there a short circuit to ground?

• Yes: Repair the circuit or install a new heated seat element as necessary. Using the manufacturer approved diagnostic system, clear the DTCs (where possible) and retest
• No: GO to  A4.

1. Refer to the appropriate system wiring diagrams and check the heated seat element circuit for open circuit, high resistance

Is the heated seat element circuit resistance within specification?

• Yes: GO to  A5.
• No: Repair the circuit or install a new heated seat element as necessary. Using the manufacturer approved diagnostic system, clear the DTCs (where possible) and retest

The seat heater power supply cycles on and off dependant on the seat and cabin temperature and may only switch on for 5 seconds in 30 seconds.

1. Reconnect the connector
2. If necessary, operate the vehicle air conditioning on full for 10 minutes to reduce the temperature of the vehicle interior
3. Connect an inductive ammeter (current clamp) to the heated seat element circuit
4. Operate the heated seats on full power
5. Use the Seat Heater Mat Application Chart to calculate a typical current value (using I=V/R, Current equals Volts divided by Resistance). For example:
   • 12 volts/0.5 ohms = 24 amps
   • 12 volts/1 ohms = 12 amps
   • 12 volts/2 ohms = 6 amps

Does the heated seat circuit draw the correct quantity of current?

• Yes: Using the manufacturer approved diagnostic system, clear the DTCs (where possible) and retest. If the operation of the heated seats is correct no further action is necessary
• No: GO to  A6.

Ensure the multimeter used is calibrated and a resistance reading of 0 ohms is shown when the test leads are connected together. Alternately, subtract any resistance shown from the result.

1. Refer to the appropriate system wiring diagrams and the Seat Heater Mat Application Chart (see above) to identify the connector and terminals
2. Disconnect the connector
3. Using a multimeter, perform resistance measurements of the heated seat element circuit and the NTC resistor circuit (where possible)
4. Compare the results to the Seat Heater Mat Application Chart

Are the results within specification at the given ambient temperature? (tolerance ± 0.5 ohms)

• Yes: Reconnect the connector. Using the manufacturer approved diagnostic system, clear the DTCs (where possible) and retest. If the fault persists, refer to the appropriate system wiring diagrams and check the power and ground circuits
• No: Repair the circuit or install a new heated seat element as necessary. Using the manufacturer approved diagnostic system, clear the DTCs (where possible) and retest